What Happens When You Take Ozempic for Weight Loss? An Endocrinologist, Aesthetic Medicine Doctor and Dietician Explain

Earlier this year, the conversation around Ozempic exploded. Currently, the drug, which is a brand name for semaglutide, has 1.2 billion views on TikTok and according to Variety, anyone who looks like they’ve lost weight in Hollywood is probably on it (Elon Musk has sung its praises, Amy Schumer tried it and many more celebs have confirmed using the drug to shed pounds). But how does Ozempic actually work? And what are the side effects? With a new pill form on the horizon, here’s everything you need to know about it, as explained by a nutritionist, endocrinologist and aesthetic medicine doctor.

• Dr. Andrew Quint, M.D., is the endocrinologist for the Diabetes Center of Excellence at Greater Philadelphia Health Action, a Federally Qualified Health Center with more than 80,000 patients in Philadelphia. Prior, he was in a private endocrinology practice for 30 years.
• Shira Barlow, MS, RD, is a nutrition expert and the author of The Food Therapist. Barlow is Goop’s resident nutritionist and has been featured in publications such as Glamour, Seventeen, Refinery 29, Bon Appétit, and POPSUGAR Fitness. She holds a master’s in clinical nutrition from New York University and completed her residency at Mount Sinai Medical Center.
• Dr. Azza Halim is a board-leading multi-specialist with a diverse background in medicine and a focus in aesthetic medicine. Her expertise includes hormone therapy, nutrition, diet, fitness, supplements and functional medicine. Dr. Halim completed her medical training at Northwestern University, with an internship in internal medicine and a residency in anesthesiology.

Ozempic is one of three injectable semaglutide products approved by the FDA to treat type 2 diabetes, along with Wegovy, authorized to treat obesity. Though the former has undeniable buzz, in terms of efficacy, one doesn’t necessarily outperform the other.

“Ozempic’s [reputation] is a little hard to understand. I think it's just word of mouth when really it’s no better or worse than the other injectables (other than Mounjaro),” Dr. Quint says. (Mounjaro is another injectable medication developed to treat type 2 diabetes, and is more effective because it contains both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP).)

What’s important to understand is that semaglutide is a type of medication classified as a GLP-1 agonist (glucagon-like-peptide).

According to Dr. Quint, GLP-1 drugs do four things: increase insulin secretion, reduce glucagon secretion, slow the emptying of the stomach and reduce appetite.

“It doesn’t affect your metabolism,” he clarifies. “It just makes you feel full, so you eat less.” Dr. Halim adds that because it slows digestion, people taking the drug will usually feel satisfied with smaller portions of food.

In the weight loss conversation, Dr. Quint notes that what the drug is really doing is helping people alter behaviors. Often times, he says, those struggling with obesity will continue to eat despite feeling full. Being on Ozempic or a similar drug will make doing so uncomfortable and using it in the long term can train people to change their eating habits in a way that sticks. However, it’s worth noting that semaglutide products aren’t a magical “fix.” Once someone stops the medication, any weight loss could come back if the person doesn’t maintain the eating habits that they developed while taking the product (as shown in this 2022 study where patients who stopped taking the medication regained about two-thirds of the weight they’d lost).  

Though Ozempic is lauded for the rapidity at which it helps patients lose weight, Dr. Halim underlines the fact that ultimately, weight loss is about lifestyle modification, and that the best results come from doing so slowly and consistently.

The GLP-1 drugs were created for those with diabetes, a BMI over 30 and/or those with/at risk of cardiovascular disease with a BMI over 27, says Dr. Halim.

While many have turned to Ozempic for cosmetic weight loss, it’s important to understand that the drugs are more effective for those who need to lose a significant amount of weight, such as obesity patients, Dr. Quint notes. “You get the most positive reinforcement and most likely prolonged behavioral change if you’re truly obese to begin with.”

As such, those with diabetes or obesity patients are the ones who tend to benefit from taking the drug in the long-term. Diabetics will take it for as long as it helps control blood sugar, Dr. Quint explains, while obesity patients may taper off semaglutide after achieving their target weight, if they can maintain it with healthy lifestyle practices.

As for those seeking to take semaglutide for off-label use, Dr. Quint raises some concerns and questions.

“In principle, it strikes me as a form of ‘abuse’ and, like other forms of substance abuse, there’s likely some underlying psychologic issue(s) that ought to be addressed,” he says. The clamor for medications has also caused a shortage for those who rely on them for serious health problems, he continues. And then, there’s the mindset. “You may have read about concerns regarding reduced muscle mass (‘sarcopenia’) and bone density in people who lose weight quickly with GLP-1s. People taking a GLP-1 for diabetes or obesity usually understand that gradual weight loss is desirable; for people wanting to look thinner for a wedding or vacation, the whole idea is to take off the weight quickly. That could be unhealthy.”

“Common side effects include nausea, vomiting, diarrhea, stomach pain and constipation and usually are mild-to-moderate and clear up in a few weeks,” Dr. Halim says.

Dr. Quint concurs, explaining that side effects can be managed, and perhaps avoided, simply by building up a tolerance to the drug. This means starting with the lowest available dose and then increasing it based on what you and your medical provider have deemed appropriate. That, and listening to your body and not eating when you feel full.

Lately, there’s been chatter about an Ozempic pill, but the truth is that an oral form of the drug received FDA approval in 2019. Sold under the name Rybelsus, it is also used to treat type 2 diabetes, though it is less effective. This is due to the fact that the amino acids and peptides don’t do well in the stomach’s acidic environment, explains Dr. Quint. “The effectiveness of the drug is much more sustained when you’re getting a shot once a week as opposed to absorbing something orally once a day.” The “new” Ozempic pill simply has a higher dosage of semaglutide than Rybelsus.

There’s been a recent outburst of news in which people taking Ozempic now have “paralyzed” stomachs, or gastroparesis, in which the patient experiences an extremely slow emptying of the stomach, or a complete stoppage. Symptoms include frequent vomiting and nausea, which persisted even after the patients stopped taking Ozempic. A CNN article reported that more of these cases are surfacing, due to the increased demand for semaglutides. However, the article also shared that the FDA still believes the benefits outweigh the risks.

“I think the risks are the same for people that have diabetes, people that are heavy, and the people that really want to use it truly off label. The risks are unusual and rare, but they're the same in all three of those groups,” Dr. Quint adds.

Though often American diet culture treats food as calories in, calories out, what we eat plays a vital role in delivering key nutrients. So what happens when you start taking a drug that makes you want to avoid food?

“Some possible nutrient deficiencies associated with semaglutide include vitamin D, B12 and magnesium,” Barlow says. “Great sources of vitamin D include fatty fish and egg yolks, although I would recommend getting levels checked and supplementing if necessary. Same with B12, which is also in meat, fish, eggs and dairy as well as magnesium which can be found in nuts and seeds. As with anything that could curb appetite significantly there is a potential for deficiencies so it’s helpful to be proactive and prioritize nutrient dense whole foods.”