No. No published clinical trial has studied retatrutide combined with testosterone or TRT. The TRIUMPH Phase 3 trials excluded participants on anabolic steroids. Any combination use is outside the studied clinical context.

There is no clinical evidence supporting or characterizing the combination of retatrutide and testosterone. Retatrutide is not FDA approved. Combining an unapproved investigational drug with testosterone carries unknown risks and should only be considered under physician supervision.

Significant weight loss — which retatrutide produces — is associated with increases in testosterone in men with obesity-related hypogonadism. This is a physiological effect of fat loss, not a direct pharmacological effect of retatrutide on testosterone.

Online communities discuss this combination for body recomposition — using retatrutide for fat loss while using testosterone to preserve or build muscle during a caloric deficit. This rationale is anecdotal and not supported by clinical evidence.

The risks are unknown because the combination has not been studied. Known risks of each compound individually include cardiovascular effects, hormonal disruption, and GI adverse events for retatrutide. Combining them introduces unknown interaction risks.