Ozempic is the most hyped diabetes drug ever. It seems like the whole world is talking about the drug, which was approved in 2017 but only became a social media weight loss sensation in 2022.
One surprising result of Ozempic’s meteoric rise has been an unprecedented public focus on the drug’s side effects. With so many people sharing their experiences in the public square, we are learning about Ozempic’s peculiar effects in a way that even a phase 3 trial could never reveal. Every few weeks, it seems, we hear that TikTok users are shining a light on another new Ozempic side effect.
This article will detail everything we know about Ozempic side effects — the good, the bad, the scientifically verified, and the anecdotal.
A brief note: This article uses the brand name Ozempic to refer to semaglutide, the drug’s active ingredient. Semaglutide is also marketed under two other names, Wegovy (when it is sold for weight loss) and Rybelsus (when it is in the form of a pill rather than an injection). Other related drugs, such as liraglutide (Victoza) and tirzepatide (Mounjaro), may or may not cause some of the same side effects.
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Gastrointestinal Side Effects: Nausea, Diarrhea, Vomiting, Abdominal Pain, and Constipation
These uncomfortable tummy troubles make up Ozempic’s most common and most discussed side effects by far.
While a majority of users don’t perceive these pains, a substantial minority do. And for some, the gastrointestinal distress is just too much to handle, and they need to stop taking Ozempic entirely. As a blogger for New York magazine’s “The Cut” put it, “You might go through Hell for your post-Ozempic body.” The author spoke to a 42-year-old woman with diabetes who endured “constant nausea” and “power-puking” for weeks, before finally weaning herself off the drug.
According to the U.S. Food and Drug Administration (PDF), placebo-controlled trials of Ozempic found the following rates of side effects from the 1 milligram (mg) dose:
- Nausea: 20.3 percent
- Vomiting: 9.2 percent
- Diarrhea: 8.8 percent
- Abdominal pain: 5.7 percent
- Constipation: 3.1 percent
Smaller numbers reported symptoms such as acid reflux and excessive belching or flatulence.
All told, 30.8 percent of adults reported a gastrointestinal symptom. But that was only the 1 mg dose, half of the maximum. The numbers were much higher in a trial of semaglutide (Wegovy) at 2.4 mg in people without diabetes:
- Nausea: 44.2 percent
- Vomiting: 24.8 percent
- Diarrhea: 31.5 percent
- Abdominal pain: 10.0 percent
- Constipation: 23.4 percent
At this, the highest dosage of semaglutide available, an incredible 74 percent of participants experienced at least one gastrointestinal disorder, though it’s worth noting that nearly 50 percent of those who took a placebo also had some tummy troubles. Only 4.5 percent of the semaglutide patients stopped taking the medication as a direct result of gastrointestinal disorders.
Reports from the Diabetes Daily forum suggest that these unfortunate effects are strongest in the days immediately after injecting the once-weekly medication. Patients are also most likely to experience problems when they start on the drug or when they step up to a higher dosage; the side effects commonly fade away as the body gets used to the medicine.
What’s the best way to deal with these nasty problems? We have an entire article on the subject.
Ozempic Burps
A foul-smelling burp isn’t exactly the most debilitating of side effects, but it’s worth knowing about. As reported in The Atlantic, and discussed in many TikTok videos, some people with Ozempic find themselves emitting nasty sulfurous smells when they belch. There is broad agreement that the burps smell like rotten eggs.
Only a minority of people experience sulfurous burps, likely fewer than 10 percent. Anecdotal reports suggest that the burps, like other gastrointestinal issues, are worst when patients begin taking their drugs or step up to higher dosages.
TikTok is full of tips, from amateurs and doctors alike, on what foods trigger eggy burps and how to get rid of them.
Bloating and Farting
These uncomfortable side effects were reported in clinical trials as “abdominal distension” and “flatulence.” Bloating and farting complaints are less common than the gastrointestinal effects discussed above, and they have yet to catch on as hot topics on social media, but it’s good to know that Ozempic and related drugs may increase their likelihood.
Ozempic Face and Ozempic Butt
“Ozempic face” may have been the first Ozempic side effect to go viral. In January 2023, everyone was talking about this rumored side effect, which was covered lavishly in the mainstream media. In June 2023, the pattern repeated itself when claims of “Ozempic butt” hit headlines. In each case, users complained that the drug had given them a surprising and unfortunate flabby appearance, in the face, in the derriere, or perhaps in both.
There’s nothing to worry about. There is no evidence that Ozempic or any other similar drug directly acts on your appearance. Experts agree that Ozempic face and Ozempic butt are purely caused by weight loss. The same flabby result can occur when you lose weight the old-fashioned way.
When you lose a lot of weight, you might also lose some of the healthy-looking fat on your face. Rapid weight loss can also lead to flabby skin: The skin is an adaptable and elastic organ, but it cannot snap instantly back into a taut shape. Successful dieters have struggled with these issues since long before Ozempic came on the scene.
Hair Loss
Ozempic can cause hair loss. While it isn’t listed as a side effect on Ozempic’s FDA label, hair loss is listed on the official label for Wegovy, essentially the same medication. Three percent of participants in the drug’s pivotal trial reported hair loss (three times as many as those who used a placebo).
Like Ozempic face and Ozempic butt, however, this isn’t a worrying chemical effect of the drugs but rather an inevitable consequence of rapid weight loss. Dramatic weight loss, no matter how it’s caused, often causes hair loss. For example, a 1974 study of crash dieters found multiple cases of “profuse hair loss.” And more than half of people who receive bariatric surgery experience hair loss, too.
The good news: A 2017 study found that “hair loss stopped and new hair gradually grew out in all patients.” Hopefully, the minority of Ozempic users that lose some hair on the drug will have the same good luck.
Fatigue
There are reports that Ozempic can cause fatigue — basically, tiredness or exhaustion that isn’t improved by sleep. The FDA label for semaglutide (Wegovy) reports that 11 percent of trial participants experienced fatigue, a little bit more than twice as often as those who used a placebo.
It’s unclear why Ozempic would cause fatigue, although one very plausible explanation is the fact that it causes people to eat so much less food. Ozempic causes extreme weight loss by encouraging users to eat at an extreme calorie deficit. You’re putting less fuel into your body. Is it any wonder that a crash diet can sap your energy?
Dizziness
Dizziness has also been reported in a slim minority of Ozempic users. It is possible that Ozempic dizziness stems from the glucose-lowering effects of the drug — dizziness is a common symptom of hypoglycemia. Even patients who are not at risk of severe hypoglycemia (typically those that do not use insulin or sulfonylureas) may feel dizzy while experiencing transient low blood sugar episodes.
Muscle Loss
It is inevitable that weight loss will involve some muscle loss. This is considered healthy and natural.
Some experts, however, believe that Ozempic and related drugs are causing a surprising and worrying amount of muscle loss, more than we see with other weight loss methods.
We only have a modicum of good data on this question. Body composition analyses of volunteers in two trials found that semaglutide users lost about 40 percent lean mass and 60 percent fat. A 2017 review states that dieters using other methods to lose weight tend to lose only 20 to 30 percent lean mass.
The science here remains unsettled; we don’t know if Ozempic causes extra muscle loss. Either way, experts agree that it would be wise for Ozempic users to engage in strength-building exercises to help preserve muscle mass during weight loss. Eating enough protein may also help.
This potential side effect may also be a good reminder that Ozempic is inappropriate for people who do not have a good medical reason to lose weight.
Ozempic Dreams
Behold, the most beguiling of all Ozempic side effects: the Ozempic dream. In April, The Wall Street Journal reported that many users were experiencing strange vivid dreams, often involving celebrities.
It’s impossible to know if this is a real side effect or just a social media confabulation, though some experts have speculated on ways that the drug — or the weight loss it creates — could enhance vivid dreaming.
Addictive and Compulsive Behavior Relief
Many Ozempic users are amazed to find that they are engaging in less addictive and compulsive behavior. Somehow the drug appears to reduce our damaging tendency to overindulge in activities like drinking, shopping, gambling, or to compulsively pick at our skin or bite our nails. The Atlantic recently wondered, “Did scientists accidentally invent an anti-addiction drug?”
The science here is still in its infancy, but it appears that one of the reasons Ozempic is able to stem hunger cues is by acting directly in the brain. We know that Ozempic doesn’t just help you feel full faster, it actually lowers your craving for food. And it seems as if it reduces your craving for other things, too.
Experts have known for years that GLP-1 receptor agonists might have these behavioral effects. In a 2022 study of exenatide (Byetta), brain scans showed that the drug lowered activity in “crucial brain areas for drug reward and addiction.” It also calmed down the brain’s dopamine circuitry.
We are years away from the day that Ozempic or any related drug will be prescribed as a therapy for addictive or compulsive behavior. But in the meantime, it could help users with more than just compulsive eating.
Heart Rate Increases
There’s been surprisingly little online chatter about this side effect, which is noted on Ozempic’s FDA label. In clinical trials, lower doses of Ozempic “resulted in a mean increase in heart rate of 2 to 3 beats per minute.” Some patients, like a woman profiled by The Cut, found the experience extremely uncomfortable.
The FDA advises patients to “inform their healthcare providers of palpitations or feelings of a racing heartbeat while at rest.” Patients that experienced “sustained” increases in resting heart rate should discontinue the medication.
Worsening Eyesight
People with diabetes should know that there is some evidence that semaglutide (Ozempic) may increase the incidence of diabetic retinopathy. One of several pivotal studies of semaglutide found an increased risk of DR, and the FDA has reported that a significantly higher percentage of Ozempic users have DR in comparison with users of similar drugs like dulaglutide (Trulicity) and liraglutide (Victoza). The connection is disputed, however, as another large study of semaglutide found no such risk.
If the connection is real, it seems possible that Ozempic’s incredible effectiveness explains its negative effect on the eyes. Contrary to all expectations, rapid improvement in glucose control can actually worsen diabetic retinopathy. This is called “early worsening,” because the eyes will get worse before the major long-term benefits of better blood sugar control become evident.
A recent discussion of the issue by experts from the American Academy of Ophthalmology suggested that “early worsening” from Ozempic is both “temporary and manageable,” although it does call for increased scrutiny from eye doctors.
Hypoglycemia
While Ozempic probably does not itself cause hypoglycemia, its glucose-lowering effect can sharply increase the odds that insulin or sulfonylureas cause hypoglycemia.
If you have diabetes and you’re starting a new GLP-1 receptor agonist, it’s possible that you’ll need to change the dosages of the other diabetes drugs that you use. Your doctor may also ask you to be extra vigilant about checking your blood sugar. If you’re not comfortable changing your insulin-dosing practices by yourself, you should be ready to contact your doctor between visits to get clearance for making adjustments.
Rare, Serious Side Effects
Semaglutide also leads to a small number of rare but potentially serious side effects:
- Pancreatitis, in which the digestive enzymes attack the pancreas, may feel like intense stomach pain that radiates to your back.
- Kidney failure. There have been some cases of semaglutide contributing to kidney disease. Dehydrating side effects, particularly diarrhea and vomiting, may enhance this risk.
- Gallbladder disease may present with severe stomach pain, yellowing of the eyes or skin, fever, and “clay-colored stools.”
- Thyroid C-cell tumors. It’s unknown if semaglutide actually causes these potentially cancerous tumors in humans, but it has been observed in studies of rodents.
There have also been some reports of allergic reactions to GLP-1 receptor agonists.
Ozempic is powerful stuff: If you’re experiencing a reaction that you can’t explain, please reach out to your healthcare provider.
