Benefits
Immune markers after strenuous exercise
Hard exercise can briefly dip some immune markers. In small placebo-controlled trials in trained men, 30 to 60 days of a nucleotide supplement left salivary IgA higher after the supplement period in two studies from one lab, and sped lymphocyte recovery in elite athletes, but salivary IgA did not differ in that athlete trial. No trial counted colds or infections.
Muscle damage markers and recovery after resistance exercise
In a crossover trial of 10 men and 10 women, a nucleotide supplement lowered cortisol right after a heavy resistance session and creatine kinase, a muscle damage marker, 24 hours later, and force output stayed higher over the next two days. Blood immune cell counts did not differ. An earlier 30-man trial using a short maximal test found no change in creatine kinase or lactate.
Gut comfort ratings in adults with sensitive bowels
In a crossover trial of 37 adults with diagnosed irritable bowel syndrome, a yeast nucleotide capsule taken three times daily for 8 weeks lowered symptom ratings about 4 to 6 percent more than placebo, mainly abdominal pain and incomplete emptying. Bloating, wind and diarrhoea did not differ. The capsule also held fructo-oligosaccharides, glutamine and vitamins, and the maker funded the study.
Muscle function and body composition in older adults
In 69 adults aged 60 to 75, two nucleotide products taken for 10 weeks improved physical performance tests and one thinking-speed test versus placebo, while the placebo group lost muscle and gained fat. A 19-week trial of 1.2 g/day in 121 older adults found about 0.5 kg more skeletal muscle and less fatigue than placebo. These are single trials with surrogate outcomes.
Long use as an infant formula ingredient
Nucleotides occur in breast milk and are added to many infant formulas. A pooled analysis of infant trials linked nucleotide-fortified formula with stronger antibody responses to some routine vaccines and fewer diarrhoea episodes, and one trial found a stool bacteria pattern closer to breastfed babies. Infants are a different case, and these results do not carry over to adults.
Mechanism of action
Building blocks for fast-dividing cells
Immune cells and the cells lining the gut divide quickly and need nucleotides to make new DNA and RNA. The body normally makes enough itself and also recycles nucleotides through salvage pathways; dietary nucleotides are thought to spare this work during growth, injury or heavy physical stress. This conditionally essential idea rests mostly on animal and infant studies.
Possible damping of the exercise stress response
Several exercise trials found lower cortisol after hard sessions with nucleotides, alongside changes in immune markers. Cortisol is a stress hormone that rises with intense exercise; whether the lower cortisol explains the immune findings has not been tested in people.
Purine breakdown to uric acid
Adenine and guanine nucleotides are purines. Once absorbed, the body breaks extra purines down to uric acid. Controlled feeding studies with nucleotide-rich foods showed blood uric acid rising within hours and staying higher over a week of high intake, which is why dose matters for people prone to gout.
Clinical trials
Randomized trial with nucleotide, placebo and no-supplement groups for 60 days, with a 2-minute maximal exercise test before and after (Mc Naughton et al. 2007, J Sports Med Phys Fitness).
30 moderately trained men, 10 per group.
After supplementation, salivary IgA was higher and post-exercise cortisol lower in the nucleotide group than in both control groups. Blood lactate, lactate dehydrogenase and creatine kinase did not change. The groups were small and no infection outcome was recorded.
Randomized, placebo-controlled trial of a free-nucleotide product (Inmunactive, 480 mg/day) for 30 days, with an exhaustion test in a cold chamber before and after; funded by the maker, Bioiberica (Riera et al. 2013, J Int Soc Sports Nutr).
20 elite male taekwondo athletes, 10 per group.
Lymphocyte counts recovered faster after exercise in the nucleotide group (higher at 150 minutes) and lymphocyte proliferation was higher after supplementation. Salivary IgA did not differ between groups. No infections were tracked.
Double-blind, placebo-controlled randomized trial of 50 mg/day nucleotides held under the tongue for 14 days (Ostojic et al. 2012, J Int Soc Sports Nutr).
38 healthy young men aged 20 to 25 (19 per group).
Serum IgA and natural killer cell count and activity rose, and the post-exercise drop in salivary immunoglobulins and lactoferrin was smaller than with placebo. Fasting salivary antimicrobial proteins did not change and no side effects were reported. The sublingual route differs from swallowed capsules.
Double-blind crossover trial in which each participant did a heavy resistance session after a loading period on a nucleotide supplement or placebo (Sterczala et al. 2016, J Strength Cond Res).
20 adults (10 men, 10 women).
With nucleotides, cortisol and myeloperoxidase were lower right after the session, creatine kinase was lower at 24 hours, and isometric squat force was higher immediately and at 24 and 48 hours. Neutrophil, lymphocyte and monocyte counts showed no treatment effect.
Randomized, double-blind, placebo-controlled crossover trial of IntestAidIB, one 500 mg capsule three times daily for 56 days per phase; funded by the supplier (Dancey et al. 2006, Nutr J).
37 adults with diagnosed irritable bowel syndrome.
Symptom ratings improved about 4 to 6 percent beyond placebo, most for incomplete evacuation and abdominal pain; diarrhoea, bloating and flatulence differences were not significant, and no psychological measure changed. The capsule also contained fructo-oligosaccharides, glutamine, amino acids and B vitamins.
Randomized, controlled, parallel-group feeding trial: 7 days of a controlled diet with high-nucleotide or nucleotide-depleted mycoprotein at lunch and dinner; several authors were funded by or employed at the mycoprotein maker (Coelho et al. 2022, Clin Nutr ESPEN).
20 healthy adults.
Fasting serum uric acid rose from 295 to 472 micromol/L by day 6 on the high-nucleotide diet, above clinically acceptable levels, and stayed flat on the low-nucleotide diet. Insulin sensitivity, 24-hour glucose and blood lipids were not affected. The nucleotides came from food, not capsules.
Double-blind, randomized, placebo-controlled trial of 1.2 g/day of a four-nucleotide blend (AMP, CMP, GMP, UMP) hydrolysed from food yeast, with capsules provided by Zhen-Ao Biotechnology (Wang et al. 2025, Adv Sci).
121 community-dwelling adults aged 60 to 70 in Chengdu, China.
DNA methylation age, a lab estimate of biological ageing, fell about 3 years more than placebo; telomere length did not differ. Insulin resistance (HOMA-IR) and fatigue scores improved and skeletal muscle rose about 0.5 kg. Uric acid rose temporarily at week 11 and returned to baseline by week 19.