Amycretin vs Retatrutide
The two most-watched next-generation weight-loss drugs
Amycretin (Novo Nordisk) and retatrutide (nicknamed "Reta," Eli Lilly) are the two investigational compounds posting the largest early weight-loss numbers in the pipeline — but they work through different receptors and are at different stages. Here is how the amylin co-agonist and the triple agonist actually compare.
Two different routes to deep weight loss
Amycretin is a single molecule that activates both the GLP-1 receptor and the amylin receptor. GLP-1 suppresses appetite and slows gastric emptying, while amylin adds a separate satiety signal and may help preserve lean mass — and uniquely, amycretin is being developed in both a subcutaneous injection and an oral tablet.
Retatrutide takes a different path: it is a triple agonist hitting GLP-1, GIP, and glucagon receptors. The added glucagon component raises energy expenditure and drives liver-fat oxidation on top of appetite suppression, which is why it has produced the largest average weight loss recorded in obesity trials so far.
Both remain investigational in 2026. Neither is FDA approved, and head-to-head trials between them do not exist — so any comparison relies on separate studies with different designs and patient populations.
Amycretin vs Retatrutide at a glance
- ⚡Mechanism: GLP-1 + amylin co-agonist
- ⚡Routes: subcutaneous injection AND an oral tablet
- ⚡Subcutaneous Phase 1b: roughly 22% mean weight loss at 36 weeks
- ⚡Amylin adds a distinct satiety pathway and may support lean-mass retention
- ⚡Status: investigational — Phase 2 ongoing, not FDA approved
- ✓Mechanism: GLP-1 + GIP + glucagon triple agonist
- ✓Route: once-weekly subcutaneous injection
- ✓Phase 3 TRIUMPH-4: up to 28.7% mean weight loss at 68 weeks
- ✓Glucagon raises energy expenditure and reduces liver fat
- ✓Status: investigational — Phase 3 ongoing, ahead of amycretin on timeline
Who is watching which?
Retatrutide is further along: it already has a positive Phase 3 readout and the deepest reported weight loss, so people prioritizing the strongest data and an earlier likely launch tend to watch it most closely. Its glucagon mechanism is also a draw for those interested in liver-fat reduction and a thermogenic effect.
Amycretin is the one to watch for an oral option — a tablet that approaches injectable-level weight loss would be a major shift in convenience — and for the amylin mechanism, which is associated with strong satiety and potential lean-mass benefits. It is earlier in development, so its data set is smaller and may change as larger trials report.
Making an informed comparison
Because amycretin and retatrutide have never been tested against each other, cross-trial numbers are an imperfect guide — differences in trial length, dosing, and participants mean the percentages are not directly comparable. Treat the data as directional, not definitive, and expect both profiles to sharpen as Phase 2 and Phase 3 results mature through 2026 and beyond.
Whatever you are on now, tracking your own response in Shotlee — weight trend, appetite, side effects, and labs — gives you an objective baseline. If amycretin or retatrutide becomes available, that history lets you compare outcomes with precision instead of guesswork.
Amycretin vs Retatrutide: Frequently Asked Questions
There is no head-to-head trial, so neither is proven better. Retatrutide has reported the deeper weight loss (up to 28.7% in Phase 3) and is further along, while amycretin is notable for an oral option and the amylin mechanism. Both are investigational, and cross-trial numbers are not directly comparable.
Amycretin is a GLP-1/amylin co-agonist (available as an injection and a pill); retatrutide is a GLP-1/GIP/glucagon triple agonist (injection only). Amylin drives satiety; glucagon adds energy expenditure and liver-fat reduction.
Amycretin is being developed in both subcutaneous and oral (tablet) forms. An oral GLP-1/amylin co-agonist approaching injectable-level weight loss is one of the main reasons it is closely watched.
Both are investigational in 2026. Retatrutide is in Phase 3 with additional readouts expected, putting it ahead on timeline; amycretin is in Phase 2. Approval timing depends on trial results and regulatory review — neither is available outside trials today.
Yes. Shotlee lets you log doses, weight, appetite, side effects, and labs for your current protocol now, so you have clean comparison data ready if either drug launches. It is free.
Track Your Protocol in Shotlee
Free dose logging, weight trends, and side effect tracking — ready for whatever launches next.