Apitegromab and Trevogrumab are each a myostatin antibody.
Same target, different schedules: Apitegromab monthly; Trevogrumab in the trial schedule.
| Comparison | Apitegromab Apitegromab · SRK-015 | Trevogrumab Trevogrumab · anti-GDF8 |
|---|---|---|
| How it works | How it works Myostatin is your body's brake on muscle growth. Blocking it lets muscle hold on better. The clever part of this one is which form of myostatin it grabs. | How it works Trevogrumab blocks myostatin, the brake on muscle growth. The interesting part of this trial is what happened when a second brake was blocked at the same time. |
| What it is | An antibody tested to stop GLP-1 weight loss taking muscle along with fat. | A myostatin antibody trialled with semaglutide, where the three-drug version got dangerous. |
| Status | In trialsInvestigational | In trialsInvestigational |
| Typical dose | 10 mg/kg per dose | 200–400 mg per dose |
| How often | Monthly | In the trial schedule |
| Stays active | 24 to 31 days | Not established |
| Dose comes from | Clinical trial protocol | Clinical trial protocol |
| Cycled? | Given for the length of the trial, with no cycling Clinical trial protocol | Given through a 26-week weight-loss phase, then a 26-week holding phase Clinical trial protocol |
| What it does | ||
| Drug class | Myostatin antibody | Myostatin antibody |
| Used for | An experimental antibody given alongside a weight-loss drug, to keep more muscle while still losing fat. | An experimental antibody given alongside semaglutide, to lose more fat and less muscle. |
| Receptors hit | — | — |
| Numbers | ||
| Full dose line | 10 mg/kg per month (trial dose) | 200 or 400 mg (trial doses) |
| Why that cycle | The 24-week trial ran without a break. Nothing is known about what happens to the muscle that was preserved once the drug stops. | The trial design splits into losing weight and then keeping it off. The second half is testing whether the drug alone holds the result, and those results are not out yet. |
| Weight / effect | Not measured in a trial | Not measured in a trial |
| Chain length | Not disclosed | Not disclosed |
| Common vial | — | — |
| Before you start | ||
| Route | Into a vein | Into a vein |
| Do not use if | Not available outside a clinical trial Pregnancy No safety record outside the trial setting | Not available outside a clinical trial Pregnancy No safety record outside the trial setting |
What separates them
Staying on it. Apitegromab is taken continuously. Trevogrumab is normally run in blocks with breaks, though for this one the block length is convention rather than a tested schedule.
What doesn't differ: They are both taken the same way (into a vein) and aimed at the same thing (fat loss + muscle). Neither has a measured effect size from a published trial, so there is no number to rank them on.
What people actually report
Apitegromab
- Only tested in trials, and only alongside tirzepatide.
- People kept more muscle but lost slightly less total weight.
- Signs of an allergic reaction during or after an infusion
- Anything unusual, since the safety record is short
Trevogrumab
- Only tested in trials, and only alongside semaglutide.
- The three-drug version of the trial had two deaths and far more dropouts.
- Signs of an allergic reaction during or after an infusion
- Anything unusual, since the safety record is short
Side effects are what users and trials report most often, not a complete list. Anything sudden, spreading, or breathing-related is an emergency regardless of which compound caused it.
People also compare
This comparison does not cover cost, long-term safety, or how you personally will respond. Effect figures come from separate trials in different populations and are not always directly comparable to each other. Nothing here is medical advice or a recommendation to use any of these. Talk to a clinician about your own situation.