Enicepatide (Roche's CT-388): what it is, and how it compares to semaglutide, tirzepatide, retatrutide and the amylins

This is general educational information, not medical advice and not a suggestion to obtain or use any substance. Enicepatide is an investigational drug that is not approved anywhere and cannot be legally bought or prescribed. Nothing here is dosing, stacking or purchasing guidance, and cross-trial numbers below come from separate studies — they are not head-to-head comparisons.

If you follow the obesity-drug pipeline, a new name showed up at the American Diabetes Association's 2026 meeting in New Orleans and refused to leave the headlines: enicepatide. It is Roche's, it is injectable, once a week, and in its Phase 2 trial it produced roughly 22.5% weight loss at 48 weeks — the kind of number that only tirzepatide and retatrutide had reached before. This article is the plain-language version: what enicepatide is, where it sits next to semaglutide, tirzepatide, retatrutide, cagrilintide and eloralintide, how far along the research actually is, and whether it makes any sense to combine it with anything — the CagriSema question, and the biohacking-forum "reta + cagri" question.

What enicepatide actually is

Enicepatide is the newer name for a molecule you may already know by its code: CT-388 (also written RO7795068). It came to Roche through the December 2023 acquisition of Carmot Therapeutics for about $2.7 billion, and Roche/Genentech has been pushing it hard ever since.

Mechanically, it is a once-weekly subcutaneous dual GLP-1/GIP receptor agonist — one molecule that switches on two of the gut hormone receptors involved in appetite and blood sugar. That much it shares with tirzepatide. What sets it apart is how it hits those receptors:

• Balanced, not lopsided. Tirzepatide leans much harder on the GIP receptor than on GLP-1. Enicepatide is engineered for roughly equal activation of both — a genuinely different pharmacological profile, not just a stronger version of the same thing.
• Signalling-biased. This is the technical headline. Enicepatide is designed to trigger the useful "cAMP" signal inside the cell while recruiting very little β-arrestin — the protein that normally pulls a receptor back inside the cell and switches it off. Less of that internalisation means the receptor stays responsive longer, which is the mechanistic reason Roche gives for the drug's durable effect and the fact that weight loss had not plateaued at 48 weeks.

You do not need the biochemistry to use the takeaway: enicepatide is a refined dual agonist that tries to stay effective for longer per dose, rather than a brand-new class of drug.

The Phase 2 numbers

The data everyone reacted to came from a Phase 2 study (CT388-103) in 469 adults with overweight or obesity, testing five doses from 4 mg to 24 mg against placebo over 48 weeks. It showed a clean dose-response curve, and at the top dose:

• ~22.5% placebo-adjusted weight loss at 48 weeks (efficacy estimand), with no plateau yet — the curve was still heading down when the trial window closed.
• Among people on the 24 mg dose at week 48, 95.7% lost at least 5% of their body weight, 87% lost ≥10%, 47.8% lost ≥20%, and 26.1% lost ≥30%.

It was not free of side effects. As with every drug in this class, the trouble is mostly gastrointestinal — nausea, vomiting, diarrhoea — and discontinuations due to adverse events were 5.9%, versus 1.3% on placebo. That is a real number, but it sits in a normal range for potent incretin drugs.

On the strength of that, Roche launched its Phase 3 programme, ENITH, in early 2026, with a realistic launch somewhere around 2030. In other words: the efficacy signal is strong, and the timeline is long.

How it differs from the drugs you already know

Here is the landscape, and the single most useful thing to understand is that these molecules are not all doing the same job. Some hit incretin receptors (GLP-1, GIP, glucagon); others mimic amylin, a different satiety hormone entirely.

A few honest words on each, because the table flattens real differences:

• Semaglutide is the one-receptor original. Everything newer is, in some sense, an answer to "can we beat pure GLP-1?" Our semaglutide reference has the background.
• Tirzepatide was the first to prove two receptors beat one. Enicepatide's pitch is that it engages those same two receptors more evenly and more durably — see the tirzepatide reference for the incumbent it is measured against.
• Retatrutide adds a third receptor, glucagon, and currently posts the highest incretin weight-loss numbers of all — we covered its latest Phase 3 read-outs in Retatrutide TRIUMPH-2 and TRIUMPH-3 and the full picture lives on our retatrutide reference. Enicepatide is not trying to out-muscle it; it is trying to get similar results from a cleaner two-receptor design.
• Cagrilintide and eloralintide are not incretins at all — they are amylin drugs, working through a separate satiety pathway. That distinction is the whole reason the next section exists.

One caution you should carry through all of this: none of these numbers are head-to-head. Different trials, different lengths, different populations. A 22.5% in one study and a 24% in another do not settle which drug is "stronger" — only a direct trial can do that, and most of those have not been run.

Can you combine it? CagriSema, "reta + cagri", and Roche's own answer

This is the question that fills forums, and it is worth answering carefully, because the popular framing is a little confused.

First, the taxonomy. CagriSema is not two GLP-1 drugs — it is one GLP-1 drug (semaglutide) plus one amylin drug (cagrilintide) in a single pen, hitting two different hormone systems. That is the important pattern: the entire industry is converging on "incretin + amylin" as the next step, because the two pathways suppress appetite in complementary ways rather than piling onto the same receptor.

Once you see that, the combination question answers itself:

• Stacking two incretin drugs is mostly pointless. Enicepatide already covers GLP-1 and GIP. Adding semaglutide (more GLP-1) or tirzepatide (more of the same two) does not open a new mechanism — it just doubles the receptor you are already hitting, which tends to add side effects without adding much benefit. That is why no serious programme develops "GLP-1 plus another GLP-1."
• The rational partner is an amylin. And here is the tell: Roche is doing exactly this. Alongside enicepatide it is developing petrelintide, an amylin analog (~9% weight loss on its own at 42 weeks), and in mid-2026 it started a Phase 2 trial of the two combined — a fixed-dose enicepatide + petrelintide, explicitly to chase more weight loss with better tolerability. Novo's version of that idea is CagriSema; Lilly's is tirzepatide + eloralintide. Roche's is enicepatide + petrelintide. Same recipe, three kitchens.
• The biohacking "reta + cagri" stack — retatrutide plus cagrilintide — is the grey-market echo of the same logic: a triple incretin plus an amylin. Mechanistically it rhymes with what the companies are testing. Practically, it is a different animal: there is no controlled human safety data for the do-it-yourself version, the side effects (nausea, vomiting, dehydration, and the discontinuations that go with them) stack too, and every vial in that scenario is unregulated material of unverified identity and purity. The fact that a combination makes pharmacological sense in a sponsored trial does not make a self-mixed version safe, dosed correctly, or legal.

So: can you combine enicepatide? On paper, the sensible combination is enicepatide with an amylin, not with another GLP-1 — and that combination is being built by Roche itself, under clinical supervision, years before anyone can buy either piece.

What this means for you today

Be clear-eyed about the timeline. Enicepatide is investigational. It is not approved anywhere, you cannot get a prescription for it, and the Phase 3 programme points to a possible launch around 2030. Anything sold online right now as "enicepatide" or "CT-388" is, by definition, unapproved grey-market material of unknown identity and purity — a committee slide deck and a clinical trial do not vouch for a vial a stranger mailed you. If you want the wider legal picture, our pillar on whether peptides are legal walks through the categories, and what peptides are is the ground-up primer.

For the drugs people actually do track today, the neutral part is the arithmetic. If you keep a record of what you have, at what concentration, and when, our peptide tracker is built for exactly that; if reconstitution is the shaky step, our calculator turns a target dose into the units on the syringe once you know the vial strength and the bacteriostatic water you added; and because these are weekly injections whose levels rise and fall between shots, the level plotter draws that curve. None of that is a recommendation to use anything — it is the maths, kept honest.

Bottom line

Enicepatide (CT-388) is Roche's balanced, signalling-biased GLP-1/GIP agonist, and its ~22.5% Phase 2 weight loss earns it a real seat at the table next to tirzepatide and retatrutide — with a cleaner two-receptor design and a longer runway to market. The combination story is the more interesting one: the field has moved on to incretin + amylin, and Roche's own answer is enicepatide plus petrelintide, not enicepatide plus another GLP-1. Stacking two incretins is redundant; the DIY "reta + cagri" version borrows the right idea and none of the safety data. For now, enicepatide is a drug to watch, not a drug to get — because you can't, and the version a forum sells you is not the version that produced these numbers.

Sources

• Roche, Positive Phase II results for its dual GLP-1/GIP receptor agonist CT-388 (enicepatide)
• Roche, New data advancing its obesity portfolio at the ADA 2026 Scientific Sessions
• Roche, Positive Phase II results for petrelintide, an amylin analog
• Medical Dialogues, Roche obesity drug enicepatide delivers 22.7% weight loss in mid-stage trial
• PMC / peer-reviewed, Effects of CT-388, a once-weekly signaling-biased dual GLP-1/GIP receptor agonist
• Lilly, Selective amylin agonist eloralintide — Phase 2 results
• HCPLive, CagriSema achieves 22.7% weight loss in Phase 3 REDEFINE 1