Nutrae Blog · Ingredient primer · Reviewed 2026-07-18

Urolithin A

What Urolithin A is, which formulations human studies used, and why findings cannot be transferred automatically to the planned capsule.

In plain language

What it is.

Urolithin A presented as a planned single-ingredient capsule with source-linked research context.

Urolithin A is a defined ingredient. Nutrae keeps its planned capsule specification separate from studies of proprietary formulations.

Human evidence

What researchers measured.

Human studies used specific Urolithin A formulations and reported mixed study-specific outcomes. They do not test the planned Nutrae capsule.

A2022

Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial

Design: Randomized, double-blind, placebo-controlled trial · 66 adults aged 65 to 90 years

Form, dose and duration: Proprietary urolithin A formulation · 1,000 mg/day · 4 months

Reported result: The primary six-minute-walk and maximal ATP-production outcomes were not significantly better than placebo. Selected muscle-endurance measures improved versus placebo at two months, but not consistently at four months because of placebo-group improvement. Some biomarkers improved.

Important limit: Small trial, all participants were White, COVID-related disruption occurred and selected positive secondary findings require confirmation.

Primary record
A2022

Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults

Design: Randomized, double-blind, placebo-controlled trial · 88 healthy overweight middle-aged adults randomized; 79 completed

Form, dose and duration: Proprietary urolithin A formulation · 500 or 1,000 mg/day · 4 months

Reported result: The primary peak-power outcome did not improve significantly. Hamstring average torque improved by approximately 12% with 500 mg and 9.8% with 1,000 mg versus placebo, and maximum flexion torque improved by approximately 10.6% and 10.5%. Broader quadriceps, handgrip, walking and aerobic outcomes were mostly not significant between groups.

Important limit: Some positive findings were secondary endpoints, the sample was modest, and the studied proprietary formulation is not automatically equivalent to Nutrae's capsule.

Primary record
A2026

Effects of Urolithin A Supplementation on Muscle Health Outcomes in Humans from Randomized Controlled Trials

Design: Systematic review and meta-analysis of randomized controlled trials · 5 randomized trials with 236 participants

Form, dose and duration: Urolithin A formulations used across the included trials, predominantly proprietary formulations · Varied across included studies, generally within 250 to 1,000 mg/day · Short-term trials up to approximately 4 months

Reported result: Only the six-minute-walk outcome could be pooled: mean difference 17.03 metres, 95% confidence interval -5.33 to 39.40, p=0.135, I-squared 0%. Other strength, endurance and biomarker signals were heterogeneous and exploratory.

Important limit: Only five heterogeneous trials, small samples, short durations and substantial reliance on company-sponsored proprietary formulations.

Primary record
The Nutrae boundary

What this does not prove.

Principal trials used proprietary formulations. Equal nominal milligrams do not establish equal exposure or clinical equivalence for a finished Nutrae capsule.

No finished Nutrae product has been tested in a randomized human trial. Ingredient studies do not establish an outcome for this capsule or show that it produces the same exposure as another formulation.

Safety context

Use the final label.

Urolithin A was generally well tolerated in relatively small, short human studies. Longer-term safety, uncommon adverse effects and medicine interactions remain less certain.

  • Most human safety data come from small, short studies using proprietary formulations.
  • Pregnancy, nursing, medicine use, medical conditions and planned surgery require qualified medical advice.
Read the complete collection

Three molecules, kept separate.

Compare Ca-AKG, NR and Urolithin A without turning one ingredient’s evidence into another product’s claim.

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