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Is Hair Loss a Side Effect of Wegovy and Ozempic?

Are people taking Wegovy and Ozempic (semaglutide) to lose weight also losing hair? Why does Wegovy reveal this problem but Ozempic does not?

The hottest drugs in weight control these days are Wegovy and Ozempic. Ozempic does not have FDA approval for weight loss, but this injectable diabetes drug contains the exact same ingredient as Wegovy, which is approved for weight management. Because of media attention, both drugs are currently in short supply. There is growing concern, though, that semaglutide, the ingredient in both medications, may have an unanticipated side effect—hair loss!

The FDA’s Hair Loss Warning with Wegovy and Ozempic Is Confusing:

The FDA approved Ozempic to treat type 2 diabetes in 2017. In 2021 the agency gave the identical drug (semaglutide) a green light under the name Wegovy to help people lose weight.

In its June 4, 2021 announcement the FDA wrote that this once-weekly, self-injected medicine is:

“…for chronic weight management in adults with obesity or overweight with at least one weight-related condition (such as high blood pressure, type 2 diabetes, or high cholesterol), for use in addition to a reduced calorie diet and increased physical activity.”

The official prescribing information for Wegovy offers data on two large, long-term placebo-controlled trials.

In one study, 3% of the people taking Wegovy reported hair loss. In the other study, 4% of the people taking Wegovy reported hair loss.

If you look at the official prescribing information for Ozempic, however, there is no mention of hair loss as a side effect. Remember, this is the identical drug, semaglutide.

A Dirty Little Secret About Randomized Controlled Trials (RCTs):

Drug companies have become amazingly adept at influencing the collection of side effect information. Remember, these are randomized, placebo-controlled clinical trials. In theory, neither the health professionals conducting the studies nor the patients participating in the trials know who is getting the active drug and who is getting the placebo. This is supposed to eliminate bias or influence.

We have discovered, however, that the companies that conduct these studies can influence the outcome. Remember that Wegovy and Ozempic are the exact same medicine. The side effects should be quite similar with both drugs, even though one is prescribed for type 2 diabetes and the other is prescribed for weight loss.

In the clinical trials, however, 20.3% of the patients on Ozempic report nausea while only 6.1% of the people taking placebo report nausea.

Contrast that with Wegovy. Between 42 and 44% of subjects self-injecting this weight loss drug experienced nausea and 16 to 18% of those getting placebo shots complained of nausea. Take a sec to look at those numbers again and reflect upon their significance.

Diarrhea was also way different depending upon which drug patients were taking. Those in the Ozempic trials reported an incidence of diarrhea of about 8.8%. The people getting placebo in these trials reported a low likelihood of the runs: 1.9% of the time.

Contrast those numbers with Wegovy! The participants in the Wegovy clinical trials experienced diarrhea at a rate of 22 to 30%. Even more interesting is the placebo data from Wegovy. The people in these trials received injections that contained no active drug and yet they reported diarrhea 16 to 19% of the time. In other words, those getting placebo were 10 times more likely to experience diarrhea in the Wegovy trial than in the Ozempic trial.

Why Do Side Effects Vary Between Wegovy and Ozempic?

We will not bore you with our explanation for how this happens in this article. You can read our hypotheses about this “anomaly” at this link.

Randomized Controlled Trials (RCTs): A Flawed Gold Standard

Hair Loss with Wegovy but NOT Ozempic:

Why would the clinical trials of Wegovy reveal hair loss as a side effect, but not those for Ozempic? We describe a likely possibility in our article above.

The bottom line is that we suspect hair loss was not on the radar scope during the Ozempic clinical trials. If you don’t ask about a possible side effect, you will not discover it during the trial.

That would also explain the discrepancy in placebo responses of the two trials. The investigators conducting the Ozempic clinical trials may not have asked about diarrhea. Hence, a low likelihood of only 1.9% of the time for those getting placebo shots.

By the time the Wegovy trials were conducted, however, the investigators were well aware of this possible side effect. As many as 19% of those getting placebo shots reported diarrhea.

Do we really think the background rate of diarrhea is 10 times more common in people who are overweight than those who have type 2 diabetes? It’s possible, but we suspect the investigators performing the Wegovy trials asked about diarrhea more forcefully than those doing the Ozempic trials. As a result, the official prescribing information describes diarrhea as common for Wegovy but far less likely with Ozempic. Remember…it’s the same drug!

Why Does Weight Loss Lead to Hair Loss?

Nausea and lack of appetite are well known consequences of semaglutide. That may partially explain how Wegovy and Ozempic lead to weight loss. Here is just one reader’s account of this effect:

Liz lost a lot of weight on Ozempic, but the side effects were too much for her:

“I am severely overweight. Two years ago my doctor prescribed Ozempic. I was able to lose 60 pounds because the drug made me feel full. While I was taking it, I just did not think about food.

“I stopped taking the drug because the “intestinal apocalypse” became too intense. At first, I had an attack every couple of months. When it became twice a month, that was it for me.

“When these attacks occurred, I ended up sitting on the toilet with diarrhea while throwing up in the bathroom trash can. I was totally miserable and lost 10 days of work. One attack was so bad I ended up in the emergency room because of dehydration.”

Telogen Effluvium After Rapid Weight Loss:

If people really stop eating, as some do, they can become malnourished. That is an unusual but worrisome side effect. Eating disorders could also become worse on semaglutide or similar medicine such as tirzepatide (Mounjaro).

Starvation diets or extreme weight loss can also lead to hair loss. The human body often responds to stress with something called telogen effluvium. Hair stops growing and falls out. You can learn a lot more about why this happens at this link.

How to Keep Your Hair from Falling Out

Dermatologists are familiar with this reaction, but physicians in other specialties may not think to warn patients about it. In our experience, hair loss is not a drug side effect that physicians like to mention. We list a range of common medications that can trigger this adverse reaction at this link.

Could Your Medicine Cause Hair Loss?
Many doctors are unaware that the medications they prescribe can cause hair loss. Alopecia is not life threatening but it is important!

Other Side Effects of  Wegovy and Ozempic:

Some doctors may consider losing hair a “minor” complication of drugs like Wegovy and Ozempic. Many prescribers may believe it is too trivial to mention. And yet we have received painful messages from both women and men who watch their hair collect in the shower drain after taking certain blood pressure medications or pain pills.

Other adverse reactions linked to Wegovy and Ozempic include vomiting, diarrhea, abdominal pain, gallbladder problems, fatigue, pancreatitis and thyroid tumors. The incidence of nausea is 44%. Diarrhea weighs in at 30%. Vomiting and constipation show up at 24%. Abdominal pain occurs at 20%. Headache is listed as 14%. There are lots more side effects that are less common, but we won’t bore you with them.

One other complication of semaglutide has to do with what I will refer to as “rebound.” I don’t think of it the way I think of rebound hyperacidity associated with powerful acid suppressing drugs such as proton pump inhibitors, though. It is regaining weight once the drug is stopped.

As described above, there are some pretty nasty side effects linked to semaglutide. As a result, some people like Liz stop self-injecting the medicine. We have heard from those who regain weight when they stop the medicine. You can read more about this phenomenon at this link.

Will Ozempic or Wegovy Weight Loss Last?
Semaglutide can help people lose serious weight. But what happens to Wegovy weight loss when you stop using the drug? Will you regain pounds?

Please share your thoughts about Wegovy and Ozempic in the comment section below.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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