What is Inosine (Inosine)?
Inosine is a purine nucleoside composed of hypoxanthine and ribose; it is formed by the deamination of adenosine and from inosine monophosphate (IMP) via 5'-nucleotidase action. It is an intermediate molecule in purine metabolism and is broken down by purine nucleoside phosphorylase (PNP) into hypoxanthine, and subsequently via xanthine oxidase into uric acid. It also plays a role in signal transmission through adenosine receptors (A1, A2A, A2B, A3).
- CAS number: 58-63-9
- Molecular formula: C₁₀H₁₂N₄O₅
What is Inosine Used For? Why is it Used?
The use of inosine for sports performance is not recommended due to existing evidence being NEGATIVE, and this information should be stated honestly. Its current scientific value lies more in purine metabolism, adenosine receptor signaling, and its neuro-/cardioprotective potential in the research stage. As a B2B component, it should be positioned in the context of scientific research and nucleotide metabolism rather than ergogenic claims.
Usage as Sports Nutrition
The following information is based on sports nutrition research (ISSN position stands, randomized controlled trials, and meta-analyses); the level of evidence is clearly stated for each item.
- Ergogenic claim — EVIDENCE IS NEGATIVE (honest): Inosine has been presented as ergogenic based on the assumption that it increases ATP production and oxygen transport; however, controlled studies have NOT SHOWN any performance benefit. McNaughton et al. (1999, PMID 10660865) reported that 10 g/day of inosine was INEFFECTIVE on aerobic/anaerobic cycling performance and 2,3-DPG; Starling et al. (1996, PMID 8883009) reported no benefit in endurance/sprint performance and that it could be HARMFUL under certain conditions. Level of evidence: CLEARLY NEGATIVE.
- Possible adverse effects: Studies have shown that high doses of inosine increased uric acid levels, and some data indicated it could worsen performance or show negative metabolic markers (e.g., increased uric acid). Therefore, it is NOT RECOMMENDED as a sports supplement.
Forms and Differences
Inosine is available in different forms; form selection is made based on bioavailability, stability, and intended use:
- Inosine (pure nucleoside): It is a purine nucleoside where the ribose sugar is attached to the hypoxanthine base (NOT an amino acid; its nutritional classification is a nucleoside). It is found in supplements in pure powder/capsule form.
Usage in Dietary Supplements
- Historical ergogenic use: It was marketed as a sports supplement in the 1980s-1990s on the grounds that it would increase ATP resynthesis and oxygen transport via 2,3-DPG in erythrocytes. HONESTLY: These claims have NOT BEEN VERIFIED in controlled studies.
- Current research areas (non-sports): Current scientific interest is mostly directed toward neuroprotective, cardioprotective, and immunomodulatory potential (e.g., stroke, Parkinson's, MS research); these are in the experimental/clinical research stage and do not constitute supplement claims.
Usage in the Food Industry
- Flavor enhancer (nucleotide derivatives): Inosine and related nucleotides (especially inosine-5'-monophosphate, IMP) are known in the food industry as umami flavor enhancers; inosine nucleoside itself is mostly for supplements/research purposes, while IMP is evaluated as a flavor additive.
Effects on Health
- Purine metabolism and uric acid: Inosine converts to hypoxanthine → xanthine → uric acid in the purine catabolic pathway; its intake raises plasma uric acid. Although uric acid is a potent antioxidant, high levels increase the risk of gout.
- Adenosine receptor signaling: Inosine exerts effects via adenosine receptors (A1/A2A/A2B/A3); this is the presumed mechanism for its neuroprotective and immunomodulatory effects in the research stage.
- Urate elevation (research): Inosine has been investigated in some neurological clinical trials (e.g., Parkinson's urate studies) to intentionally raise urate levels; this is a research context, not an established treatment.
Status of Health Claims (EFSA) — Transparent Information
There is NO authorized (approved) health or performance claim for inosine in the EU, and no ergogenic claim has been approved by EFSA. Independent sports science literature has found the evidence for inosine's ergogenic (performance-enhancing) effect to be NEGATIVE (PMID 10660865; PMID 8883009); some data have reported it may be harmful to performance.
Usage Limits and Safety
- Typical usage dose: The dose used in performance studies was typically 5,000-10,000 mg/day (for 5-10 days); while these doses were tolerated acutely, they raised uric acid and did not provide a performance benefit. There is no general 'recommended' supplement dose.
- Upper intake level (UL): There is NO established Tolerable Upper Intake Level (UL) (stated honestly). The main safety concern is elevated uric acid; it should be avoided in individuals with gout or hyperuricemia.
- Turkish legislation (Sports Foods / TETGK): Inosine is a purine nucleoside (not an amino acid); no specific numerical upper limit for inosine has been published in the Turkish Food Codex Dietary Supplements Regulation (NO FABRICATION — it does not exist). The use of a component in supplements is subject to the general Regulation and notification/evaluation processes.
Warning: High doses of inosine RAISE URIC ACID → risk of gout/hyperuricemia and possible kidney stones. It should not be used in individuals with gout, hyperuricemia, or kidney problems. Performance benefit has not been proven.
Technical Specifications
| Parameter | Value |
|---|---|
| Moisture | ≤5.0 % |
| Total Heavy Metals | ≤10 ppm |
| E. Coli | Negative in 10 g |
| Salmonella | Negative in 25 g |
| Solubility | Soluble in Water |
Scientific Studies
The following independent studies relate to the component's effect on sports performance, bioavailability, and efficacy (study types are specified):
- PubMed 10660865 — Inosine supplementation has no effect on aerobic or anaerobic cycling performance
- PubMed 8883009 — Effect of inosine supplementation on aerobic and anaerobic cycling performance
Technical Documents and Supply — Asuka Kimya
You can contact Asuka Kimya for SDS, TDS, CoA, and supply conditions for Inosine.
References
- pubmed.ncbi.nlm.nih.gov
- pubmed.ncbi.nlm.nih.gov
- academic.oup.com
- pubmed.ncbi.nlm.nih.gov
- pubmed.ncbi.nlm.nih.gov
The usage, sports nutrition, and health information on this page have been compiled from official legislation/institution sources (EFSA, NIH ODS, ISSN, Turkish Food Codex Sports Foods / Dietary Supplements Regulation) and independent scientific publications (PubMed). The product is a food supplement/sports nutrition raw material; it does not intend to diagnose or treat diseases.