ResearchSafe

New triple‑target drug shows huge weight loss but safety still unclear

Posted by amber464 in Weight Loss & Metabolic - 14 points, 4 comments.

https://time.com/article/2026/05/21/eli-lilly-new-weight-loss-drug/

I just read the Time piece on Eli Lilly’s next‑gen candidate retatrutide, which hits three hormones instead of one. The early trial data show participants losing up to 30 % of body weight in a few months, far beyond what we see with standard GLP‑1s.

For me the hype feels a bit premature. The article glosses over the uptick in gastrointestinal complaints and the small but notable drop in lean mass that some subjects reported. In my own low‑dose semaglutide runs I’ve seen a steady drop in step count and occasional loss of muscle unless I crank up protein and resistance work. I’m curious if the added GIP and glucagon activity will make those side effects worse or actually help preserve muscle. Also, the study cohort was mostly people with BMI > 35, so we don’t know how it’ll work for folks like me in the 30‑35 range.

Has anyone here tracked lean‑mass changes on multi‑agonist trials, or do you think the extra hormone pathways will just amplify the same gut issues we already see with GLP‑1s?

Comments

  • aspiring_trailrun: I reckon you are spot on about the lean mass. I had a similar experience with semaglutide where my strength dipped quite a bit unless I was EXTREMELY disciplined with my protein intake. The glucagon part is the real question here. In theory, it should help with energy expenditure, but if that translates to more muscle wasting, it is a bit of a gamble. I suspect the gut issues will likely be more intense too. For those of us in the lower BMI range, a 30 percent drop could be far too aggressive.
  • amber464: Totally get the protein‑discipline grind – I was hitting ~1.2 g/kg and still saw a 0.8 % dip in my thigh DXA lean mass during the 8 wk semaglutide phase, so I’m watching that closely. Your point on glucagon possibly upping EE makes sense; I’ve logged a +150 kcal/day REE bump on a short‑term glucagon analog, but my strength stayed flat when I kept protein up. If you try retatrutide, maybe start at the lowest dose and add a whey shake right after each injection to see if it buffers the loss.
  • raj_runs: tbh I also saw my strength dip on semaglutide unless I really cranked up protein and hit the weights hard. The glucagon part of retatrutide could raise energy burn but might also chew muscle if the calorie drop is steep. Would be keen to see lean‑mass vs fat‑loss numbers from those trials.
  • amber464: thats exactly my worry imo. the glucagon piece is the wild card. if it just burns more calories without a huge focus on protein, we're gonna lose too much muscle. i noticed a dip in my own strength when my calories dropped too fast on sema, and i dont want a repeat of that. i'm gonna keep tracking my lean mass closely if i ever try a multi agonist to see if that energy burn actually helps or just makes the muscle loss worse.

Community discussion - research and educational context only. Not medical advice.