The research database for performance-enhancing drugs, peptides, hormones, and human optimization. Understand what was tested, what changed, and what the evidence cannot tell us.
For athletes, coaches and research-minded readers. Evidence, not protocols.
Three ways to read the evidence: a landmark experiment, a peptide trial and a safety finding. An editorial selection—not a benefit ranking.
Landmark human researchHuman · 1996Abstract summarized · Quality not appraised
Testosterone plus exercise increased fat-free mass by 6.1 kg; bench-press strength rose 22 kg and squat capacity 38 kg. Testosterone without exercise also outperformed placebo for measured muscle size and strength. Mood and behavior were unchanged.
Study context & limitations
Randomized trial comparing weekly testosterone enanthate or placebo, each with or without standardized resistance training.
Forty-three normal men received 600 mg testosterone enanthate or placebo weekly for 10 weeks; exercise groups lifted three times weekly.
This was a small, 10-week study in normal men using a supraphysiologic regimen. The abstract reports mood and behavior but no longer-term safety assessment or author-stated limitations.
Peptide trialHuman · 2023Abstract summarized · Quality not appraised
At 48 weeks, average weight loss was 24.2% in the highest-dose group versus 2.1% with placebo.
Study context & limitations
A randomized, blinded trial compared retatrutide with placebo for weight loss over 48 weeks.
338 adults with obesity, or overweight plus a weight-related condition, participated.
Digestive side effects were common and dose-related. Heart rate also increased with dose. These findings describe this trial's population and follow-up.
Safety findingsHuman · 2010Abstract summarized · Quality not appraised
The trial stopped early after more cardiovascular-related adverse events with testosterone: 23 men versus 5 with placebo. Testosterone improved leg-press and chest-press strength and loaded stair climbing.
Study context & limitations
Randomized trial comparing daily testosterone gel with placebo for 6 months, with adverse events and physical performance assessed.
The trial enrolled 209 community-dwelling men aged at least 65 with mobility limitations and low testosterone; mean age was 74, with substantial chronic disease.
The authors cautioned that the small trial and its medically complex, mobility-limited population prevent broad conclusions about testosterone safety.