Benefits
Mitochondrial Health Support (via Urolithin A)
Urolithin A, the validated component of the blend, supports mitochondrial health by promoting mitophagy. Clinical trials of direct urolithin A report improved markers of mitochondrial function, which is the core rationale for Sabrolithin® A&B.
Muscle Endurance and Strength (via Urolithin A)
Trials of urolithin A in middle-aged and older adults have reported improvements in muscle endurance and strength over months of use. Honest context: these results are for urolithin A specifically, not the A+B combination.
Mitophagy Activation
Urolithin A is among the most studied natural inducers of mitophagy, the cellular process that clears damaged mitochondria. This distinguishes it from ordinary antioxidants and underlies its longevity and muscle positioning.
Bypasses Gut-Conversion Variability
Only a minority of people efficiently convert dietary ellagitannins into urolithins. Supplying preformed urolithins directly bypasses this individual variability, a practical advantage of a urolithin supplement over pomegranate or walnut intake.
Emerging Urolithin B Interest (Preliminary)
Urolithin B has shown effects on muscle-protein pathways in preclinical models, prompting interest in combining it with urolithin A. Honest context: robust human evidence for urolithin B is lacking, so its contribution remains speculative.
Mechanism of action
Mitophagy Induction (Urolithin A)
Urolithin A activates mitophagy by upregulating pathways that tag and clear dysfunctional mitochondria, supporting renewal of the mitochondrial pool — the best-characterized mechanism in the urolithin family.
Mitochondrial Biogenesis Support
Beyond clearing damaged mitochondria, urolithin A is reported to support mitochondrial biogenesis signaling, helping replace cleared mitochondria with functional ones in muscle tissue.
Urolithin B Anabolic Signaling (Preclinical)
Urolithin B has been reported in preclinical models to influence muscle-protein synthesis and degradation pathways. This mechanism is the rationale for the A+B blend but has not been confirmed in rigorous human trials.
Clinical trials
First-in-human randomized, double-blind, placebo-controlled study of direct urolithin A (single and 4-week multiple doses up to 1,000 mg/day) in healthy, sedentary older adults.
Healthy sedentary elderly adults.
Urolithin A was safe and bioavailable and induced a molecular signature of improved mitochondrial and cellular health, including favorable changes in skeletal-muscle mitochondrial gene expression. Establishes the urolithin A evidence the blend relies on.
Randomized, double-blind, placebo-controlled trial of direct urolithin A (500 mg and 1,000 mg/day) over 4 months in middle-aged adults, assessing muscle strength, exercise performance, and mitochondrial biomarkers.
Middle-aged adults.
Urolithin A was associated with improved muscle strength and biomarkers of mitochondrial health. Results are specific to urolithin A and underpin the honest framing for the A+B blend.
Randomized clinical trial of direct urolithin A (1,000 mg/day) versus placebo in older adults, evaluating muscle endurance and mitochondrial health.
66 older adults.
Urolithin A significantly improved muscle endurance in hand and leg muscles versus placebo. Again, the evidence is for urolithin A specifically; A+B-combination human data remain thin.