How to Join a GLP-1 Clinical Trial: Finding a Real Obesity Drug Study

A clinical trial is the only legal way to take an unapproved obesity drug such as retatrutide, and it is not a reliable way to get one. On October 17, 2026, ClinicalTrials.gov listed 25 recruiting trials with an open US site for six pipeline drugs: retatrutide, orforglipron, CagriSema, amycretin, survodutide and MariTide.^[1] Only one of them tests retatrutide, and it enrolls people with fatty liver disease. Most of the 25 need a second condition, such as sleep apnea, knee arthritis or heart disease. Some exclude anyone who has ever taken a GLP-1. In a placebo-controlled trial you may get the placebo, and when the trial ends, the drug usually ends too. Real trials never charge you to join.

How to find a real trial on ClinicalTrials.gov

ClinicalTrials.gov, run by the National Library of Medicine, is the registry that US law points to. Every consent form for an FDA-regulated trial covered by the registration law must tell you that a description of the trial is posted there.^[15] That makes it the first place to look and the place to check anything you find elsewhere.

1. Search by drug, not just by condition. Put the drug name in the “Intervention/treatment” field and “obesity” in “Condition/disease.” A condition search alone returns hundreds of diet, exercise and surgery studies.
2. Search the code name too. Companies often register trials under a lab code. On October 17, 2026, a search for “amycretin” returned no recruiting trials. A search for its code, NNC0487-0111, returned 11.^[1] Retatrutide is also LY3437943, orforglipron is LY3502970, survodutide is BI 456906 and MariTide is AMG 133.
3. Filter to “Recruiting.” “Not yet recruiting” and “Active, not recruiting” trials are not enrolling.
4. Check each location’s own status. A trial can be recruiting overall while sites near you are not. One CagriSema trial listed 99 US sites, and none was recruiting yet.^[1]
5. Read the eligibility section before you call. It is in every record, and it rules most people out in a minute.
6. Contact the site, not a middleman. Each location lists a coordinator. The first step is usually a phone screen, then a screening visit with blood tests.

What was actually recruiting in October 2026

We counted recruiting interventional trials for six drugs in late-stage development, by brand and code name, and kept those with at least one US site marked as recruiting.^[1] Orforglipron is already approved for weight management as Foundayo, so its open trials test new uses. The last column is the honest one: could an adult whose only diagnosis is obesity or overweight enroll?

Two findings stand out. First, almost no recruiting US trial will take someone who simply wants the newest weight-loss drug. The large weight-loss trials for retatrutide, CagriSema and MariTide have already enrolled, and the open ones target people with a second disease. Second, retatrutide is the drug people search for most, and its one open US trial is a liver study that also tests tirzepatide against placebo.^[3] Lilly says retatrutide is available only to participants in its trials.^[2] For the drug’s approval timeline, see retatrutide’s price and release date.

Searching for an “Ozempic clinical trial” mostly turns up studies of semaglutide for new conditions, because Ozempic and Wegovy are already approved. If you qualify for an approved drug, a prescription is a faster route than a trial. The drug-by-drug evidence is on our pages for amycretin, MariTide, survodutide and cagrilintide, and the wider pipeline is on our GLP-1 pipeline tracker.

How eligibility works, and why current GLP-1 users are often excluded

Every trial sets inclusion and exclusion criteria so that the results answer one question cleanly. For obesity drugs, three kinds of rule do most of the filtering.

• Body mass index. The standard cutoff is a BMI of 30 and up, or 27 and up when a weight-linked problem like high blood pressure is present. STEP 1 and SURMOUNT-1 both used it.^[9][10] Some newer trials target narrower groups. Lilly’s ATTAIN-NOW trial of orforglipron wants people with a BMI of 25 to 29.9 and a borderline risk marker, and it excludes anyone with a documented obesity diagnosis, high blood pressure or high cholesterol.^[6]
• A second condition. Many trials exist to win a new indication, so they require the disease being studied: sleep apnea, knee arthritis, heart failure, fatty liver, type 2 diabetes. MariTide’s cardiovascular outcomes trial takes adults aged 45 and over with established heart or blood-vessel disease.^[25] Diabetes can also work the other way. AMAZE 1 excludes anyone with diabetes or an HbA1c of 6.5% or higher.^[4]
• Past and current weight-loss drugs. This is the rule that surprises people. AMAZE 1 excludes anyone treated with any GLP-1-based drug or amylin analog before screening, at any time.^[4] ATTAIN-NOW excludes anyone who took a weight-loss medicine, including over-the-counter products, in the 180 days before screening.^[6] Novo’s RENEW 4, which tests cagrilintide alone and uses the same standard BMI cutoff, excludes anyone who has ever taken an amylin-based drug and anyone on a prescription weight-loss medicine in the past 180 days.^[26] Prior drug use muddies the comparison with placebo.

A few trials want current users. Amgen is recruiting adults who have already lost at least 10% of their weight on a weekly GLP-1, at a stable dose, to test switching them to MariTide. That trial has no placebo arm, and it excludes anyone with diabetes or a family history of medullary thyroid cancer.^[5] If you are already on semaglutide or tirzepatide, search for “switch” in the trial title. Do not stop a drug you are taking to qualify for a trial without talking to your prescriber, and see what happens when you stop semaglutide first.

Screening also involves blood tests, a physical exam and often an ECG, and the most common outcome of a screening visit is not qualifying. ClinicalTrials.gov notes that some studies require you to change or stop other medicines while you take part.^[8]

Your odds of getting the placebo

Most trials that matter for approval compare the drug with a placebo, an injection or pill that looks the same and contains no drug. Neither you nor the clinic staff usually knows which you are getting. ClinicalTrials.gov lists not getting the drug being tested as one of the basic risks of joining.^[8] The randomization ratio in the protocol sets your odds.

Placebo does not mean nothing happens. Placebo groups get the same diet and exercise counseling, and in STEP 1 they lost 2.4% of body weight over 68 weeks, against 14.9% on semaglutide.^[9] In STEP 4, people switched to placebo after 20 weeks on semaglutide regained 6.9% of their weight over the next 48 weeks.^[11] Some designs promise everyone the drug at some point. ATTAIN-NOW has arms that cross over from drug to placebo and from placebo to drug.^[6] Registry records list the arms but usually not the ratio, so ask the coordinator directly: “What are my chances of placebo, and for how long?”

What happens when the trial ends

In most trials, the drug stops when your part of the study stops. Nothing in the federal consent rules requires a sponsor to keep supplying an unapproved drug afterward.^[15][16] The weight data show why that matters. In the STEP 1 extension, people who came off semaglutide and the lifestyle program had put back about two-thirds of their earlier loss twelve months later.^[12]

• Extension trials exist but are not promised. Amgen is running extensions that let people from its earlier MariTide trials continue. Some of those people are re-randomized to placebo, and people who had placebo before are offered the drug. Only former participants can join.^[7]
• Expanded access rarely applies. FDA’s “compassionate use” pathway is for patients with a serious or immediately life-threatening condition who have no satisfactory alternative and cannot enroll in a trial.^[13] Obesity alone, with approved drugs available, generally does not meet that test.
• Approved drugs are the bridge. If the trial drug helped you, the realistic next step is an approved drug in the same family, prescribed by your own doctor. Our guide to switching between GLP-1 drugs covers what is known about moving between them.

Before you sign, ask in writing: will I be told which arm I was in when the study ends, is there an extension, and what does the study doctor recommend for my care afterward?

Paid weight loss clinical trials: what the rules say

Paying participants is legal and common. FDA’s guidance to review boards calls it “a common and, in general, acceptable practice” and treats the money as a recruitment incentive, not a benefit to be weighed against the risks.^[14] FDA does not set an amount. Its rules shape how payment works instead:

• Payment must be reviewed. The amount and schedule go to the institutional review board (IRB) before the study starts, and the board checks that neither is coercive. FDA says payment “should be just and fair.”^[14]
• Payment should build up as you go. It should not depend on finishing the whole study. A small completion bonus is allowed if it is not coercive.^[14]
• Travel is separate. FDA does not regard reimbursement for travel, parking and lodging as undue influence.^[14]
• Costs must be disclosed. The consent form must list any extra costs you may face from taking part.^[15] Many studies cover the study drug and research-related tests and visits, but you or your insurer still pay for your regular care.^[8]

The amount varies by study, and the consent form is where it appears.^[8] Any figure quoted on a recruitment ad that is not in the IRB-approved consent form is advertising, not a promise.

Your rights: informed consent and the IRB

Two sets of federal rules protect trial participants: FDA’s at 21 CFR part 50 for drug trials, and the Common Rule at 45 CFR part 46 for federally funded research. Both require informed consent, and both require an IRB, an independent committee, to approve the study and its consent form.^[15][16] The consent form must tell you, among other things:

• That the study is research, its purpose and how long you will be in it, and which procedures are experimental.^[15]
• The foreseeable risks, any expected benefits, and the alternatives available to you, such as approved drugs.^[15]
• For studies with more than minimal risk, whether any compensation or treatment is available if you are injured, and whom to contact.^[15]
• That taking part is voluntary, and that you may stop at any time without penalty or loss of benefits you are otherwise entitled to.^[15][16]
• That a description of the trial will be posted on ClinicalTrials.gov.^[15]

Under the Common Rule, the form must open with a short summary of the key reasons you might or might not want to join, and you must have enough time to discuss it in conditions that minimize pressure.^[16] You can take the form home. A site that wants a signature the same day, on the phone, or before answering questions is not following the spirit of the rules. If something goes wrong, the consent form names an IRB contact separate from the study team.

How to spot a fake trial

Pipeline obesity drugs are sold illegally online, and some sellers borrow the language of research. FDA has warned companies that put research-only labels on semaglutide, tirzepatide, retatrutide, survodutide and mazdutide while shipping them straight to consumers along with dosing directions.^[24] A product sold that way is not a trial, whatever the website calls it. Our guide to research-chemical GLP-1 listings explains the pattern.

A ClinicalTrials.gov listing is not proof either. The site says plainly that the government “does not review or approve the safety and science of all studies listed,” and that its staff check records only for apparent errors and inconsistencies.^[17] One sponsor shows why that matters. A company called Hudson Biotech has eight records marked as recruiting, each at the same hospital in Shenzhen, China. Together they cover a familiar list: retatrutide, tirzepatide, tesamorelin, BPC 157, TB-500, GHK-Cu, Melanotan II and MOTS-c.^[1][18] The TB-500 record’s summary begins by calling itself “fictional.”^[19] The tesamorelin record’s title ends in “Mock Study.”^[20] The tirzepatide record carries the name SURMOUNT-1,^[21] the name of Lilly’s real tirzepatide trial, which finished in 2024.^[22] The retatrutide record is the second of the two recruiting retatrutide trials worldwide.^[18] We draw no conclusion about the company’s purpose. The point is that a registry entry can say anything its sponsor types. Our MOTS-c evidence review covers the same sponsor’s MOTS-c listing.

Lilly, which makes retatrutide, says no one should take anything sold as retatrutide outside a Lilly-sponsored trial.^[2] For a real trial of a big-company drug, the sponsor on ClinicalTrials.gov will be the company itself, the sites will be named clinics and hospitals, and you will never be asked for money.