Molecular Knowledge Base
A scientific reference for bioactive compounds — mechanism of action, key characteristics and published scientific references for every molecule.
The content on this page is provided for scientific information purposes only. It does not constitute medical advice, diagnosis, treatment, or usage recommendations. EFBA accepts no responsibility for outcomes arising from the use of this information. Please consult a healthcare professional for any health-related decisions.
GHK-Cu
PeptideCopper-chelating tripeptide studied for tissue repair and collagen biology
Overview
GHK-Cu (Glycyl-L-Histidyl-L-Lysine Copper) is a naturally occurring human copper-binding tripeptide that declines with age. It has been studied in wound healing and tissue remodelling through stimulation of collagen, elastin and glycosaminoglycan synthesis, together with antioxidant and anti-inflammatory activity at the cellular level.
Mechanism of Action
GHK-Cu (glycyl-histidyl-lysine-copper) is a tripeptide-copper complex derived from the collagen alpha chain. Acting as a copper chaperone, it delivers copper to fibroblasts, activating lysyl oxidase—an enzyme that forms cross-links in tropocollagen to reinforce tissue integrity. It also modulates expression of over 1,000 genes, coordinating tissue repair, antioxidant defense, and anti-inflammatory responses.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
BPC-157
PeptidePentadecapeptide derived from a gastric juice protein, studied in preclinical tissue-repair models
Overview
BPC-157 is a 15-amino acid synthetic peptide derived from a protective gastric juice protein. In preclinical studies it has been reported to influence healing responses in tendon, ligament, muscle and gastrointestinal tissue, primarily through upregulation of growth factor receptors and promotion of angiogenesis at injury sites.
Mechanism of Action
BPC-157 is a synthetic 15-amino-acid gastropeptide stable in human gastric juice. It upregulates growth hormone receptor expression, stimulating VEGF-driven angiogenesis and the GH/IGF-1 axis; in preclinical models this has been associated with faster healing in tendon, ligament, muscle and mucosal tissue. It has also been reported to suppress pro-inflammatory cytokines, modulate nitric oxide synthase and influence gastrointestinal mucosal barrier function.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
TB-500
PeptideThymosin Beta-4 analogue studied for cell migration and tissue repair
Overview
TB-500 is a synthetic peptide analogue of Thymosin Beta-4, an actin-sequestering protein abundant in platelets and wound fluids. By upregulating actin polymerization and cell migration, it has been studied for effects on healing in muscle, tendon, joint and skin tissue models and on local inflammation.
Mechanism of Action
Thymosin β-4 (TB-500) binds actin with high affinity, regulating the intracellular G-actin pool and controlling actin polymerization. It interacts with integrin-linked kinase (ILK) to activate the Akt2 pathway and metalloproteinase production, triggering migration of epithelial and endothelial cells. It has been reported to influence mobilization and differentiation of stem/progenitor cells, to modulate angiogenesis and to inhibit apoptosis and inflammation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
CJC-1295
PeptideLong-acting GHRH analogue stimulating pulsatile growth hormone release
Overview
CJC-1295 is a modified analogue of growth hormone releasing hormone (GHRH) engineered for extended bioavailability. It stimulates the anterior pituitary to secrete growth hormone in a physiological pulsatile pattern; its effects on body composition, recovery and metabolic function are studied in research settings.
Mechanism of Action
CJC-1295 is a synthetic analogue of the hypothalamic growth hormone-releasing factor (GHRH) 1-29 fragment. After injection, it covalently binds endogenous albumin, extending its half-life substantially; it binds GHRH receptors on pituitary somatotrophs to increase GH synthesis and secretion. It maintains GH pulsatility while sustaining elevated IGF-1 levels.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
MOTS-c
PeptideMitochondrially-encoded peptide regulating metabolic homeostasis
Overview
MOTS-c is a 16-amino acid peptide encoded within the mitochondrial 12S rRNA gene. It translocates to the nucleus during metabolic stress, activating AMPK-dependent pathways that regulate insulin sensitivity, exercise adaptation and ageing-related signalling.
Mechanism of Action
MOTS-c is a 16-amino-acid mitochondria-derived peptide encoded by the 12S rRNA region of the mitochondrial genome. It targets the folate cycle to trigger AICAR accumulation and activate AMPK, thereby increasing glucose utilization and influencing insulin sensitivity. Under metabolic stress, it translocates to the nucleus and regulates nuclear gene expression via PGC-1α-dependent mechanisms.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Selank
PeptideSynthetic tuftsin analogue heptapeptide studied for anxiolytic, cognitive and immunomodulatory effects
Overview
Selank is a synthetic analogue of the immunomodulatory tetrapeptide Tuftsin. It modulates GABA-A receptors and serotonergic tone and upregulates BDNF expression; anxiolytic and cognitive effects have been studied in experimental and clinical research.
Mechanism of Action
Selank is a heptapeptide analogue of the endogenous immunomodulator tuftsin. It binds GABA-A receptors as a positive allosteric modulator to exert anxiolytic effects, while also regulating BDNF levels in the hippocampus and prefrontal cortex. It modulates dopaminergic, serotonergic, and monoaminergic systems, and has been studied for neurotrophic, immunomodulatory and memory-related effects.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Epitalon
PeptideTetrapeptide studied for telomere length maintenance and cellular senescence
Overview
Epitalon (AEDG) is a tetrapeptide synthesized from pineal gland extract. It maintains telomere length in normal somatic cells by upregulating hTERT mRNA expression and telomerase activity, while regulating antioxidant and neuronal gene expression to influence aging biology.
Mechanism of Action
Epitalon (AEDG) is a tetrapeptide synthesized from pineal gland extract. It maintains telomere length in normal somatic cells by upregulating hTERT mRNA expression and telomerase enzyme activity. It additionally activates chromatin through heterochromatin modification in aged cells and regulates antioxidant/neuronal gene expression.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Thymosin Alpha-1
PeptideThymic peptide studied for T cell maturation and immune regulation
Overview
Thymosin Alpha-1 is a 28-amino-acid peptide isolated from the thymus. It activates TLR receptors to accelerate T cell maturation and stimulate natural killer cells, and its effects on immune responses have been studied in immunocompromised patients and in chronic viral infection.
Mechanism of Action
Thymosin Alpha-1 (Tα1) is a 28-amino-acid peptide isolated from the thymus. It binds TLR3/4/9 receptors, activating IRF3 and NF-κB signaling pathways; it accelerates T cell maturation into CD4+/CD8+ subtypes and stimulates natural killer cells. It suppresses pro-inflammatory cytokines while increasing IL-2 receptor expression, thereby regulating immune homeostasis.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Semax
PeptideSynthetic neuropeptide studied for effects on BDNF and NGF expression
Overview
Semax is a synthetic neuropeptide combining the ACTH(4-7) fragment with the Pro-Gly-Pro tripeptide. It rapidly elevates BDNF and NGF levels in the hippocampus to produce neurotrophic effects, suppresses neuroinflammation in ischaemic models, and has been studied for effects on cognitive performance.
Mechanism of Action
Semax is a synthetic neuropeptide combining the ACTH(4-7) fragment with the Pro-Gly-Pro tripeptide. It rapidly increases BDNF, NGF, and TrkB mRNA/protein levels in the hippocampus, exerting neurotrophic effects. In ischemia-reperfusion models, it suppresses pro-inflammatory cytokine gene expression to dampen neuroinflammation and activates dopaminergic/serotonergic systems.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Ipamorelin
PeptideSelective ghrelin receptor agonist triggering GH release without cortisol elevation
Overview
Ipamorelin is a pentapeptide selective agonist at the GHSR-1a (growth hormone secretagogue receptor). By mimicking ghrelin it triggers GH release from the pituitary without significantly elevating ACTH or cortisol, distinguishing it from other GHRPs.
Mechanism of Action
Ipamorelin is a pentapeptide selective agonist at the GHSR-1a (ghrelin/growth hormone secretagogue receptor). By mimicking ghrelin, it triggers GH release from the pituitary without significantly elevating ACTH or cortisol levels—unlike GHRP-6. This selectivity allows GH release without corticoadrenal activation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Tesamorelin
PeptideSynthetic GHRH analogue studied in visceral adiposity research
Overview
Tesamorelin is a synthetic 44-amino-acid GHRH analogue engineered for resistance to enzymatic degradation. It stimulates GH release from the pituitary, inhibiting de novo lipogenesis and increasing fat oxidation; its effect on visceral fat accumulation is studied in visceral adiposity research.
Mechanism of Action
Tesamorelin is a synthetic 44-amino-acid GHRH analogue engineered for resistance to enzymatic degradation. It binds GHRH receptors on pituitary somatotrophs to stimulate endogenous GH synthesis and secretion. Elevated GH inhibits de novo lipogenesis and increases fat oxidation; the effect on visceral fat accumulation is studied in visceral adiposity research.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Superoxide Dismutase
EnzymePrimary endogenous antioxidant enzyme catalyzing superoxide dismutation
Overview
Superoxide dismutase (SOD) is a metalloenzyme that catalyzes the conversion of the superoxide radical into oxygen and hydrogen peroxide, forming the primary cellular defense against reactive oxygen species. Three isoforms exist: cytoplasmic CuZn-SOD, mitochondrial Mn-SOD, and extracellular EC-SOD.
Mechanism of Action
Superoxide Dismutase (SOD) is a metalloenzyme that catalyzes the dismutation of superoxide anion (O₂•⁻) into oxygen and hydrogen peroxide. This reaction proceeds via the redox cycling of copper (Cu,Zn-SOD) or manganese (Mn-SOD) ions at the active site. SOD constitutes the primary tier of intracellular antioxidant defense.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Catalase
EnzymeHigh-turnover heme enzyme decomposing hydrogen peroxide to water and oxygen
Overview
Catalase is one of the most catalytically efficient enzymes known, decomposing millions of hydrogen peroxide molecules per second. Present predominantly in peroxisomes, it limits H2O2 accumulation, a source of oxidative damage, and works together with SOD.
Mechanism of Action
Catalase is a heme-enzyme that catalyzes the reaction 2H₂O₂ → 2H₂O + O₂. The reaction proceeds when H₂O₂ oxidizes the enzyme's iron center to Compound I, a high-valent iron intermediate; a second H₂O₂ molecule then reduces this intermediate. Operating at an exceptionally high turnover, catalase limits accumulation of H₂O₂, which could otherwise generate hydroxyl radicals.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Glutathione Peroxidase
EnzymeSelenium-dependent enzyme reducing membrane lipid hydroperoxides
Overview
Glutathione peroxidase (GPx) is a selenium-containing enzyme family that reduces lipid hydroperoxides and H2O2 using glutathione as the electron donor. GPx acts on membrane lipid hydroperoxides and contributes to intracellular redox balance.
Mechanism of Action
Glutathione Peroxidase (GPx) is a selenoprotein containing selenocysteine at its active site. It reduces H₂O₂ and lipid hydroperoxides to their corresponding alcohols, using glutathione (GSH) as the reducing agent. The GPx4 isoform directly reduces complex lipid peroxides and has been identified as a regulator of ferroptosis.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Bromelain
EnzymeNF-κB-inhibiting cysteine protease complex derived from pineapple stem
Overview
Bromelain is a cysteine protease complex derived from pineapple stem (Ananas comosus). It inhibits NF-κB and COX-2 pathways (anti-inflammatory activity in experimental models), displays fibrinolytic activity and has proteolytic digestive activity.
Mechanism of Action
Bromelain is a cysteine protease complex derived from pineapple stem (Ananas comosus). It inhibits NF-κB and MAPK signaling pathways, suppressing iNOS and COX-2 expression and reducing production of pro-inflammatory cytokines. It also modulates the arachidonate cascade, inhibits platelet aggregation, and displays fibrinolytic activity.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Lysozyme
EnzymeInnate immunity glycoside hydrolase cleaving bacterial peptidoglycan cell walls
Overview
Lysozyme (muramidase) is a glycoside hydrolase enzyme that disrupts bacterial peptidoglycan layers, causing bacterial lysis. Abundantly present in tears, saliva, and human milk, it is a key antimicrobial component of the innate immune system.
Mechanism of Action
Lysozyme (muramidase) is a glycoside hydrolase enzyme that cleaves β-(1,4)-glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine. This disrupts bacterial peptidoglycan layers, compromising cell wall integrity and causing bacterial lysis. As a cationic antimicrobial peptide, it also provides a second defense mechanism independent of its muramidase activity.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Glutathione-S-Transferase
EnzymePhase II enzyme family catalysing glutathione conjugation of electrophilic xenobiotics
Overview
Glutathione-S-Transferase (GST) is an enzyme family that conjugates glutathione to electrophilic xenobiotics, increasing their water solubility and facilitating excretion. It is studied in cancer chemoprevention and multidrug resistance research.
Mechanism of Action
Glutathione-S-Transferase (GST) is a family of enzymes that catalyze the conjugation of glutathione (GSH) to electrophilic xenobiotics generated by cytochrome P450 metabolism. An active-site residue activates GSH to the nucleophilic GS⁻ form; this nucleophile forms conjugates with carcinogens and environmental pollutants, increasing water solubility and facilitating excretion.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Telomerase
EnzymeRibonucleoprotein complex that extends telomeres, studied in cellular senescence
Overview
Telomerase is a ribonucleoprotein complex consisting of the TERT reverse transcriptase subunit and the RNA component TERC. It maintains telomere length by adding TTAGGG repeats to chromosome ends; it is active in progenitor cells, and its activity is investigated in ageing biology and in cancer research.
Mechanism of Action
Telomerase is a ribonucleoprotein complex consisting of the TERT (reverse transcriptase subunit) and the RNA component TERC. It maintains telomere length by adding TTAGGG repeats to chromosome ends, thereby delaying cellular senescence. Its reactivation through TERT promoter mutations or epigenetic activation is investigated in cancer research.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Vitamin C
VitaminEssential water-soluble antioxidant and collagen biosynthesis cofactor
Overview
Vitamin C (L-ascorbic acid) is an essential micronutrient with wide-ranging physiological roles. As a water-soluble antioxidant it scavenges reactive oxygen species and regenerates vitamin E; as an enzyme cofactor it is indispensable for collagen hydroxylation, carnitine synthesis, and catecholamine biosynthesis.
Mechanism of Action
Vitamin C (ascorbic acid) acts as an essential cofactor for prolyl hydroxylase and lysyl hydroxylase enzymes, hydroxylating proline and lysine residues in procollagen to enable proper folding of the stable collagen triple helix. As an electron donor, it neutralizes superoxide, hydroxyl, and peroxyl radicals and regenerates vitamin E radicals.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Vitamin B12
VitaminCobalamin coenzyme essential for DNA synthesis and neurological integrity
Overview
Vitamin B12 (cobalamin) is a water-soluble vitamin essential for two key enzymes: methionine synthase, involved in DNA methylation and homocysteine regulation, and L-methylmalonyl-CoA mutase, involved in fatty acid metabolism. Deficiency is associated with megaloblastic anaemia and neurological changes.
Mechanism of Action
Vitamin B12 (cobalamin) is a cofactor for methionine synthase, catalyzing the synthesis of methionine from homocysteine and thereby contributing to production of S-adenosylmethionine (SAM), the universal methyl donor. SAM is essential for virtually all transmethylation reactions including DNA, RNA, histone, and neurotransmitter methylation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Vitamin D3
VitaminSecosteroid prohormone regulating immunity, bone metabolism, and gene transcription
Overview
Vitamin D3 (cholecalciferol) is a fat-soluble prohormone synthesized in skin upon UV-B exposure. After hepatic and renal hydroxylation to active calcitriol, it functions as a steroid hormone binding nuclear vitamin D receptors and regulating expression of over 1,000 genes across virtually all tissues.
Mechanism of Action
Vitamin D3 (cholecalciferol) is converted in the liver to 25(OH)D3, then by renal and immune cells to the active form 1,25(OH)₂D3 (calcitriol). Calcitriol binds the vitamin D receptor (VDR), heterodimerizes with the retinoid X receptor, and regulates transcription of thousands of genes; it increases intestinal calcium absorption and modulates immune pathways.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
B-Complex
VitaminEight interrelated B-vitamins essential for energy metabolism and cellular function
Overview
The B-complex encompasses eight water-soluble vitamins — B1, B2, B3, B5, B6, B7, B9, and B12 — that collectively act as coenzymes in cellular energy metabolism, DNA synthesis, neurotransmitter production, and one-carbon metabolic pathways.
Mechanism of Action
The B vitamin complex (B1, B2, B3, B5, B6, B7, B9, B12) is a group of water-soluble vitamins functioning as coenzymes in mitochondrial aerobic respiration. Their active forms (thiamine pyrophosphate, FAD, NAD+, coenzyme A) catalyze critical steps in the citric acid cycle and electron transport chain for ATP production.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Vitamin A
VitaminNuclear receptor ligand regulating epithelial differentiation and visual function
Overview
Vitamin A regulates cell differentiation and proliferation genes through its active form all-trans retinoic acid (atRA) via RAR/RXR nuclear receptors. In its 11-cis-retinal form it is essential for photoreceptor function, and it plays critical roles in immune development and epithelial integrity.
Mechanism of Action
Vitamin A regulates gene expression through its active form all-trans retinoic acid (atRA) via nuclear receptors (RAR/RXR heterodimers). This complex binds retinoic acid response elements in DNA to modulate transcription of genes governing cell differentiation and proliferation. Retinol in its 11-cis-retinal form is also essential for photoreceptor function.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Vitamin E
VitaminChain-breaking fat-soluble antioxidant that interrupts membrane lipid peroxidation
Overview
Vitamin E (α-tocopherol) acts as a chain-breaking antioxidant within lipophilic biological membranes and lipoproteins. It terminates lipid peroxidation chain reactions and is regenerated by vitamin C or glutathione, completing the antioxidant cycle.
Mechanism of Action
Vitamin E (α-tocopherol) acts as a chain-breaking antioxidant within lipophilic biological membranes and lipoproteins. It terminates lipid peroxidation chain reactions by donating a hydrogen atom to lipid peroxyl radicals; the resulting tocopheroxyl radical is regenerated by vitamin C or glutathione.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Vitamin K2
VitaminMenaquinone acting as a cofactor for γ-glutamyl carboxylase in bone and vascular matrix proteins
Overview
Vitamin K2 (menaquinone, especially MK-7) activates osteocalcin and matrix Gla protein as a cofactor for gamma-glutamyl carboxylase. Osteocalcin binds calcium in the bone matrix while matrix Gla protein inhibits calcification in vessel walls.
Mechanism of Action
Vitamin K2 (menaquinone, especially MK-7) is a cofactor for gamma-glutamyl carboxylase, which γ-carboxylates glutamate residues of vitamin K-dependent proteins. This carboxylation activates the calcium-binding capacity of osteocalcin and matrix Gla protein; osteocalcin binds calcium in the bone matrix, while matrix Gla protein inhibits vascular calcification.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Folate (B9)
VitaminOne-carbon metabolism cofactor essential for DNA synthesis and epigenetic methylation
Overview
Folate (vitamin B9) is the central cofactor of one-carbon metabolism. Its tetrahydrofolate form participates in purine and thymidine synthesis and methionine recycling, providing methyl groups for DNA and histone methylation via SAM production.
Mechanism of Action
Folate (vitamin B9) is the central cofactor of one-carbon metabolism. Its tetrahydrofolate (THF) form carries single-carbon units used in thymidine and purine synthesis and methionine recycling, thereby generating SAM to provide methyl groups for DNA and histone methylation. Inadequate folate disrupts the nucleotide pool and leads to DNA hypomethylation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Glutamine
Amino AcidConditionally essential amino acid and primary enterocyte fuel source
Overview
L-Glutamine is the most abundant free amino acid in circulation, becoming conditionally essential during catabolic states such as illness, surgery, or intense exercise. It is the principal fuel for rapidly dividing cells including intestinal enterocytes and immune cells.
Mechanism of Action
Glutamine is the most abundant free amino acid in the human body and the primary energy substrate for small intestinal enterocytes. It maintains gut barrier integrity by regulating tight junction protein expression. In immune cells it serves as a critical nitrogen source for proliferation and cytokine production, and provides the precursor amino acid for glutathione synthesis.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Arginine
Amino AcidNitric oxide precursor amino acid with vasodilatory and immunostimulatory properties
Overview
L-Arginine is a semi-essential amino acid and the exclusive precursor for nitric oxide synthesis via nitric oxide synthase enzymes. NO regulates vascular tone, platelet aggregation, and immune function. Arginine also stimulates growth hormone secretion and serves as a key intermediate in the urea cycle.
Mechanism of Action
L-Arginine is the direct precursor for nitric oxide (NO) synthesis as the substrate for endothelial nitric oxide synthase (eNOS). eNOS converts L-arginine to L-citrulline, generating NO; NO activates guanylate cyclase to increase cGMP, leading to smooth muscle relaxation and vasodilation. It also inhibits platelet aggregation and participates in the urea cycle.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Taurine
Amino AcidConditionally essential sulfonic acid with osmoregulatory and cardiac physiological roles
Overview
Taurine is a conditionally essential sulfur-containing amino acid abundantly present in the heart, skeletal muscle, retina, and CNS. It regulates intracellular calcium signaling, osmotic balance, and bile acid conjugation, while exerting broad antioxidant and anti-inflammatory effects.
Mechanism of Action
Taurine participates in mitochondrial protein synthesis by forming 5-taurinomethyluridine on mitochondrial tRNA, which influences electron transport chain activity. It scavenges hypochlorous acid directly, modulates intracellular calcium, and has been studied for effects on nitric oxide bioavailability and blood pressure.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Glycine
Amino AcidSimplest amino acid serving as collagen constituent and inhibitory neurotransmitter
Overview
Glycine is the simplest amino acid, constituting approximately 33% of all collagen residues. It acts as an inhibitory neurotransmitter at glycine receptors in the brainstem and spinal cord, and plays essential roles in glutathione synthesis, one-carbon metabolism, and bile acid and xenobiotic conjugation.
Mechanism of Action
Glycine is the dominant amino acid in the collagen Gly-X-Y repeat motif, determining triple helix stability; adequate glycine is essential for cartilage and connective tissue synthesis. In sleep regulation it activates NMDA receptors to induce peripheral vasodilation and a drop in core body temperature; as a neurotransmitter it participates in spinal cord inhibition.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Carnosine
Amino AcidBeta-alanyl-L-histidine dipeptide with pH buffering and anti-glycation activity
Overview
Carnosine is an endogenous dipeptide (beta-alanine + L-histidine) highly concentrated in muscle and brain. It serves as an intracellular pH buffer during high-intensity exercise, a carbonyl scavenger inhibiting advanced glycation end-product formation, and a zinc and copper chelator.
Mechanism of Action
Carnosine (β-alanyl-L-histidine) is a dipeptide found at high concentrations in skeletal muscle. The pKa of histidine's imidazole ring provides muscle pH buffering, buffering pH changes during intense exercise. Through non-enzymatic reaction with protein carbonyl groups it inhibits advanced glycation end product (AGE) formation and chelates metal ions.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Lysine
Amino AcidEssential amino acid required for collagen cross-linking and carnitine synthesis
Overview
Lysine is an essential amino acid that contributes to the indispensable post-translational modification enabling collagen fibril formation by generating hydroxylysine in procollagen. It is also the precursor for carnitine synthesis; carnitine transports fatty acids for mitochondrial oxidation.
Mechanism of Action
Lysine serves as the substrate for prolyl hydroxylase and lysyl hydroxylase enzymes, generating hydroxylysine in procollagen; this post-translational modification is essential for collagen cross-linking and fibril formation. Lysine is also a precursor amino acid for carnitine synthesis; carnitine transports fatty acids for mitochondrial oxidation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Cysteine
Amino AcidRate-limiting glutathione precursor and critical thiol source in protein structure
Overview
Cysteine is the rate-limiting amino acid for glutathione biosynthesis; its N-acetylcysteine (NAC) form is the most widely used clinical glutathione precursor. Through the redox state of protein thiol groups it regulates enzyme activities, signaling pathways, and cellular redox homeostasis.
Mechanism of Action
Cysteine is the rate-limiting amino acid for glutathione biosynthesis. The enzyme glutamate-cysteine ligase combines cysteine with glutamate to form γ-glutamylcysteine; GSH synthase then adds glycine to produce glutathione (GSH). The redox state of protein thiol groups determines their tertiary structure and function.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Tyrosine
Amino AcidCentral amino acid precursor for dopamine, norepinephrine, and thyroid hormone synthesis
Overview
Tyrosine is the central precursor for catecholamine neurotransmitter synthesis, converted by tyrosine hydroxylase to dopamine, then norepinephrine and epinephrine. It also serves as the building block for thyroid hormone synthesis.
Mechanism of Action
Tyrosine is the central precursor for catecholamine neurotransmitter synthesis, converted by tyrosine hydroxylase to L-DOPA and then to dopamine, norepinephrine, and epinephrine. It is also used in thyroid hormone synthesis; iodination forms the building blocks of thyroxine (T4) and triiodothyronine (T3).
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Tryptophan
Amino AcidEssential amino acid precursor for serotonin, melatonin, and NAD+ synthesis
Overview
Tryptophan is the sole dietary precursor for serotonin and melatonin biosynthesis. It is also converted to NAD+ precursor nicotinamide nucleotides via the kynurenine pathway; it participates in gut-brain axis signalling, mood, the sleep-wake cycle and immune responses.
Mechanism of Action
Tryptophan converts a portion of dietary intake to serotonin (5-HT) and then melatonin via the serotonin/melatonin pathway, and the majority to nicotinamide nucleotides (NAD+ precursors) via the kynurenine pathway. Serotonin signalling is involved in the gut-brain axis, mood, the sleep-wake cycle and gut motility.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Proline
Amino AcidAmino acid determining collagen triple helix stability and reinforcing tissue integrity
Overview
Proline frequently occupies the X and Y positions of the Gly-X-Y motif in collagen and is converted to hydroxyproline by prolyl 4-hydroxylase to increase collagen triple helix thermal stability. It also modulates oxidative stress responses via the proline cycle.
Mechanism of Action
Proline frequently occupies the X and Y positions of the Gly-X-Y motif in collagen and is converted to hydroxyproline in procollagen by prolyl 4-hydroxylase. This hydroxylation increases the thermal stability of the collagen triple helix and reinforces tissue integrity. Proline also modulates cellular responses to oxidative stress via the 'proline cycle.'
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
NAD+
CoenzymeUniversal redox coenzyme and sirtuin substrate central to cellular energy metabolism
Overview
Nicotinamide adenine dinucleotide (NAD+) is a coenzyme found in all living cells and central to oxidative phosphorylation and the TCA cycle. Beyond redox chemistry, NAD+ is a critical substrate for sirtuins, PARP enzymes, and CD38 — linking cellular energy status to DNA repair, epigenetic regulation, and aging biology.
Mechanism of Action
NAD+ (nicotinamide adenine dinucleotide) serves a dual function as an electron-carrying coenzyme in redox reactions and as a substrate for NAD+-consuming enzymes (sirtuins SIRT1-7, PARPs, CD38). Sirtuins consume NAD+ in deacylation reactions to deacetylate histones and transcription factors; NAD+ levels decline markedly with aging.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
FAD
CoenzymeRiboflavin-derived flavocoenzyme essential for mitochondrial electron transport
Overview
Flavin adenine dinucleotide (FAD) is a redox-active coenzyme synthesized from riboflavin (vitamin B2). It serves as a prosthetic group for flavoproteins and participates in the mitochondrial electron transport chain, beta-oxidation of fatty acids, and the TCA cycle.
Mechanism of Action
FAD (flavin adenine dinucleotide) is a riboflavin (B2)-derived coenzyme that catalyzes single- or two-electron redox reactions via its isoalloxazine ring. As a component of mitochondrial Complex II, it catalyzes the oxidation of succinate to fumarate and transfers electrons to coenzyme Q10, linking fatty acid β-oxidation to the respiratory chain.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Coenzyme Q10
CoenzymeLipid-soluble quinone essential for mitochondrial ATP synthesis and membrane antioxidation
Overview
Coenzyme Q10 (ubiquinone) is a fat-soluble molecule present in virtually every cell. As a mobile electron carrier in the mitochondrial inner membrane it shuttles electrons between respiratory complexes; in its reduced form (ubiquinol) it is a membrane-bound antioxidant. CoQ10 levels decline with age and statin use.
Mechanism of Action
Coenzyme Q10 (ubiquinone/ubiquinol) is a lipophilic quinone molecule in the mitochondrial respiratory chain that transfers electrons from Complexes I and II to Complex III. The Q-cycle between its fully oxidized and fully reduced forms sustains the proton gradient to feed ATP synthase. The reduced form ubiquinol is an antioxidant that breaks membrane lipid peroxidation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Glutathione
AntioxidantPrimary endogenous antioxidant tripeptide mediating thiol-based redox reactions and conjugation
Overview
Glutathione (GSH) is a tripeptide with a γ-glutamyl-cysteine-glycine structure. Via its thiol group it forms conjugates with electrophilic compounds, facilitating their excretion; as a cofactor for glutathione peroxidases it reduces H₂O₂ and lipid peroxides. The GSH/GSSG ratio is the primary indicator of cellular redox status.
Mechanism of Action
Glutathione (GSH) is a tripeptide with a γ-glutamyl-cysteine-glycine structure. Via its thiol (-SH) group it forms conjugates with electrophilic compounds, facilitating their excretion; as a cofactor for glutathione peroxidases it reduces H₂O₂ and lipid peroxides. The oxidized GSSG form is recycled by glutathione reductase; the GSH/GSSG ratio is the primary indicator of cellular redox status.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Alpha-Lipoic Acid
AntioxidantUniversal mitochondrial antioxidant cofactor active in both lipophilic and hydrophilic environments
Overview
Alpha-lipoic acid (ALA) is a natural cofactor for mitochondrial dehydrogenase complexes and a unique antioxidant. The ALA/DHLA redox couple scavenges reactive oxygen species, regenerates vitamins E and C, and recycles glutathione; its solubility in both fat and water earns it the title of 'universal antioxidant.'
Mechanism of Action
Alpha-lipoic acid (ALA) is a natural cofactor for mitochondrial pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase complexes. The ALA/DHLA redox couple scavenges reactive oxygen species including superoxide, hydroxyl, and singlet oxygen, chelates metal ions, and regenerates vitamin E, vitamin C, and glutathione. Its efficacy in both lipophilic and hydrophilic environments earns it recognition as the 'universal antioxidant.'
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Resveratrol
AntioxidantStilbene polyphenol studied for SIRT1 activation and caloric-restriction-like effects
Overview
Resveratrol is a stilbene-class polyphenolic compound synthesized in grape skins and other plants. It mimics caloric restriction through SIRT1 activation, modulates NF-κB and AMPK pathways for anti-inflammatory effects, and stimulates mitochondrial biogenesis.
Mechanism of Action
Resveratrol is a stilbene-class polyphenolic compound synthesized in grape skins and other plants. It activates SIRT1, increasing NAD+-dependent deacetylase activity — an effect described as mimicking caloric restriction. It also modulates NF-κB and AMPK pathways and stimulates mitochondrial biogenesis.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
Astaxanthin
AntioxidantMembrane-spanning xanthophyll carotenoid with antioxidant activity
Overview
Astaxanthin is a unique carotenoid with hydroxyl and keto groups at both ends. Its membrane-spanning structure quenches singlet oxygen within the lipid bilayer and upregulates intrinsic antioxidant defense genes through Nrf2 activation.
Mechanism of Action
Astaxanthin is a unique carotenoid with hydroxyl and keto groups at both ends. Its membrane-spanning structure quenches singlet oxygen and breaks peroxyl chain reactions within the lipid bilayer. It also activates the Nrf2 transcription factor, upregulating the cell's intrinsic antioxidant defense genes.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.
NMN
AntioxidantDirect NAD+ biosynthesis intermediate studied in age-related NAD+ decline
Overview
NMN (nicotinamide mononucleotide) is a critical intermediate in the salvage pathway of NAD+ biosynthesis. After cellular uptake it is converted to NAD+ by NMNAT enzymes, raising NAD+ levels that decline with age; effects on sirtuin and PARP activity are studied in research settings.
Mechanism of Action
NMN (nicotinamide mononucleotide) is a critical intermediate in the salvage pathway of NAD+ biosynthesis. After cellular uptake via transporter proteins, it is converted to NAD+ by NMNAT enzymes. In studies, NMN supplementation has been reported to raise NAD+ levels that decline with ageing; effects on sirtuin and PARP activity, metabolic function and mitochondrial biogenesis are under investigation.
Key Characteristics
Scientific References
For informational purposes only — not medical advice.