In the latest clinical trial, Eli Lilly’s retatrutide helped participants lose up to 28.7% of their body weight.Some participants dropped out of the trial because they lost too much weight.The drug is not yet FDA-approved, but there are already counterfeit products available online.<\/p>\n
Retatrutide is an experimental weight-loss drug from Eli Lilly that may be the most powerful obesity treatment yet. Unlike Wegovy and Zepbound, which target one or two hormones that help regulate appetite, retatrutide mimics three.\n<\/p>\n
In the latest clinical trial, participants lost up to about 28.7% of their body weight. The astonishing results have generated significant buzz online, but also raised concerns about its safety.\n<\/p>\n
A Weight Loss Drug That Works All Too Well <\/p>\n
For some patients, retatrutide<\/a> may be too effective. The weight loss achieved with retatrutide may approach the percentage of weight a person can shed within a year after bariatric surgery<\/a>.\n<\/p>\n While many people with obesity are eager to lose weight, excessive weight loss can carry serious risks, including malnutrition<\/a> and loss of muscle mass<\/a>. Muscle loss in particular can increase the risk of frailty, falls, and other complications\u2014especially in older adults\u2014and in severe cases, may even contribute to death.\n<\/p>\n Anyone struggling with obesity may think there is no such thing as too much weight loss,\u00a0but \u201cdoctors need to follow the response of patients to these new drugs very carefully, and monitor not just weight loss but also undernutrition and loss of muscle mass while they are on the drugs,” said William Dietz, PhD<\/a>, a professor of exercise and nutritional sciences at The George Washington University.\n<\/p>\n In a December press release<\/a>, Eli Lilly shared data from an ongoing trial showing that participants taking the two highest doses of retatrutide lost an average of up to 28.7% of their body weight\u2014about 71 pounds\u2014over 68 weeks. Between 12% and 18% of participants dropped out of the trial, many of whom had to discontinue due to excessive weight loss.\n<\/p>\n “Though weight loss on obesity medications is very patient dependent and can often be lower or higher than average,\u201d said Jamie Kane, MD<\/a>, director of the Center for Weight Management at Northwell Health in New York, and a spokesperson for The Obesity Society.\u00a0\n<\/p>\n Problem With Counterfeit Retatrutide <\/p>\n Retatrutide is still in clinical trials and has not been reviewed or approved by the Food and Drug Administration (FDA). However, a quick online search for \u201cbuy retatrutide\u201d brings up websites selling products under that name, often shipped from overseas. Sales of fake retatrutide seem to be fueled both by online influencers and individual users sharing purchase tips on Reddit and other social media sites.\u00a0\n<\/p>\n \u201cWhat those companies are selling is completely unknown. It could be a different peptide entirely, a mislabeled or counterfeit product, a product with the wrong concentration or contaminants, or something with no active ingredient at all. Every one of those scenarios carries a real risk of serious harm,” said Rozalina McCoy, MD<\/a>, vice chief of clinical research in the Division of Endocrinology, Diabetes, and Nutrition, at the University of Maryland School of Medicine.\n<\/p>\n McCoy said that because retatrutide is not yet approved, there is no FDA-approved information on the drug\u2019s optimal dosing or warnings about potential side effects such as excessive weight loss.\u00a0\n<\/p>\n People who buy retatrutide online may be more likely to start at higher doses or keep increasing the dosage on their own. Prescribing guidelines for GLP-1 drugs recommend starting at the lowest dose and gradually increasing it. However, some healthcare providers may stop at a lower dose if a patient is losing enough weight and tolerating the medication well, rather than pushing to the maximum.\n<\/p>\n Who Would Be the Right Candidate for Retatrutide? <\/p>\n Despite concerns about excessive weight loss, retatrutide will be an important addition for obesity patients when it’s approved.\n<\/p>\n “I find these early results really exciting and a much-needed advance in obesity therapy, but with an important asterisk about who this drug is actually for,\u201d McCoy said.\n<\/p>\n She noted that nearly 1 in 10 U.S. adults has severe obesity, defined as a BMI of 40 or higher<\/a>. For a typical person in that category, reaching a healthy body weight often means losing 35%-40% or more of their total body weight.\u00a0\n<\/p>\n \u201cSo, for someone who is 5\u20196\u201d and weighs 250 pounds\u2014a BMI of roughly 40\u2014would need to lose close to 90 pounds to reach a healthy weight. Until now, the only realistic path to that magnitude of weight loss was metabolic surgery. None of the other obesity medications would produce this result for the average person, so for a person with severe obesity, [retatrutide] could be genuinely transformative,” McCoy said.\n<\/p>\n Retatrutide may be right for those who medically need to lose this much weight, but it’s important for patients and providers to decide on the right treatment plan.\n<\/p>\n \u201cThe answer to the obesity epidemic is not a one-size-fits-all prescription from an online retailer,\u201d said McCoy. \u201cIt is a patient and a clinician, working together, choosing the right tool for that specific person at that specific time.\u201d\n<\/p>\n Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process<\/a> to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.<\/p>\n Medline Plus. Gastric bypass surgery<\/a>.<\/p>\n