Semaglutide, the drug famously sold under brand names like Ozempic and Wegovy, has boomed in popularity  in just a handful of years.

I am willing to bet you have heard of it. Semaglutide has been used since  2017 to control type 2 diabetes.

And was approved for weight loss in people without diabetes in 2021. Since then, it’s safe to say it’s  touched off something of a craze. This is a powerful drug, and  a lot of people are using it.

And seeing great benefits, which I love for them. However, this explosion in usage is  starting to show that semaglutide is ridiculously powerful, and not just  for the purposes it’s approved for. It’s not limited to doing just  one thing inside your body… making it a double-edged sword  with both benefits and risks.

We’re starting to learn what all those things are, and while some of it is great,  some of it is less great. So here are 5 things they’re not  telling you about semaglutide. [♪INTRO] Before we get into the first item on our list, what are this drug everyone’s talking about? It’s part of a class of drugs  sometimes referred to as GLP-1s.

That acronym technically stands  for glucagon-like peptide-1. And technically these drugs bind to the same receptor as natural GLP-1 But we’ll come back to what  that all means in just a second. The first GLP-1 drug to receive FDA approval was Exenatide in 2005, for the  treatment of type 2 diabetes.

It’s a synthetic, modified  version of a molecule found, of all places, in the saliva of Gila monsters. Scientists had observed that  these reptiles had relatively stable blood sugar despite  their infrequent yet huge meals. And it turns out that they make  a super potent version of GLP-1.

Since that first one, six more of  these drugs have been approved. And they are powerful. Nothing in your body happens in isolation.

Taking control of one big process – like blood sugar in the case of GLP-1s – is going to talk to lots of  other processes and make lots of little changes and snowball in  ways we can’t always predict. Which means taking semaglutide can  have a lot of knock-on effects. Along with the presumably desired weight loss, unwanted effects like hair loss, the gaunt appearance of so-called Ozempic face, and even Ozempic feet have  made their rounds online.

But the drug itself isn’t to blame for those headline-grabbing side effects. A fast drop in weight is known to cause visible changes when the skin doesn’t  keep up with fat loss, and hair is known to fall out in response to inadequate nutrition or rapid weight loss. So instead, today we’re going to be  talking about actual side effects, some of which are pretty surprising.

First up, there’s what  semaglutide is supposed to do. Humans have many different types of so-called receptors embedded in cell  membranes or inside cells. Each type of receptor is like a unique, complex switch in an extremely  intricate switchboard.

And each one responds to the binding of one or more signaling molecules. Any time you want to start, stop,  or change a biological process, signaling molecules and receptors  are out there directing traffic. GLP-1 is a signaling molecule  naturally produced by the body, mostly in the intestine,  in response to eating food.

It binds to the corresponding receptors  in different parts of the body, influencing processes that govern blood sugar, fat mass, insulin secretion, fullness, and more. GLP-1 drugs basically pretend to be GLP-1, letting us take control of those processes. So here’s how that works.

Insulin is often compared to a  key that unlocks the body’s cells, allowing sugar in for energy. People with diabetes may not be able to process sugar adequately on their own. Semaglutide stimulates pancreatic  cells to produce insulin far more efficiently than natural human  GLP-1, which helps lower blood sugar.

Semaglutide also seems highly  effective at reducing glucagon, which has the opposite effect of insulin — it raises blood sugar when  the cells need more energy. Glucagon levels can be too high in some people with diabetes or a higher body fat percentage, allowing too much sugar to  hang out in the bloodstream. Semaglutide dials up insulin and reduces glucagon, pulling blood sugar levels down overall.

This can protect against the harmful effects of higher blood sugar over time. In the long run, reduced blood sugar levels may lead to reduced conversion of glucose to fat. And this plays one role in the weight  loss that occurs with this drug.

But blood sugar reduction can also be a mixed bag. Semaglutide and other GLP-1 drugs can cause blood sugar to drop too low,  especially when dosage is off or when it’s used with other glucose-lowering drugs. Known effects of low blood sugar include cognitive issues and anxiety, which is one reason that doctors closely monitor  patients on these drugs.

It’s also why you should take  these drugs under the supervision of a qualified healthcare team  and avoid sketchy websites. Some doctors also advise  against taking them purely to drop a few pounds for cosmetic reasons. Semaglutide has a lot of effects on how we process and break down our meals.

So maybe it’s not surprising that it can also affect our actual digestive organs. For one, it slows the movement  of the digestive system. One way this happens is through  the activation of nerves that reduce smooth muscle  contractions in the stomach.

Semaglutide also seems to  act on the pyloric sphincter, the muscular ring between the  stomach and the small intestine, which may play a role in slowing down stomach contents from moving on. This can be helpful — keeping  contents in the stomach for longer means sugar getting into  the bloodstream more slowly. But it can also contribute  to undesirable side effects.

One of those is a condition called  gastroparesis, or stomach paralysis. This is reported to be as  unpleasant as you would imagine. It’s worth noting that diabetes itself  is known to cause gastroparesis, so diabetics risk developing it  whether or not they use semaglutide.

But here’s one fun consequence: It could affect you if you need surgery. Anesthesiologists have noticed that slow stomach emptying means stuff could stay in your stomach, even if you were very good and followed their instructions on when to stop eating. And that increases the risk of aspiration, or stuff coming back up into  your airway from your stomach during an operation.

There is disagreement among  experts on what to do about this. For a while, major professional  organizations in anesthesiology recommended stopping semaglutide  one to two weeks before surgery. Though some have walked this back, many hospitals may still require stopping the drug before a scheduled procedure.

Even stranger, there have also been reports of unexpected pregnancies, leading  to so-called “Ozempic babies.” The cause? Some have hypothesized that slow stomach movement decreases the effectiveness  of the birth control pill. There is evidence that delayed  gastric emptying may affect the way the body processes other drugs,  especially those that rely on speed of digestion or other time-related  internal logistics for their efficacy.

These include some over-the-counter  drugs like Tylenol, or prescriptions like certain statins. But it varies from drug to drug. Some medications seem to be processed fine with slower stomach emptying.

One small study suggests that  birth control pills are among those that should be effective, even  with the slowed GI movement. Instead, some of these surprise pregnancies could result from an increase  in fertility that can come with reduced body fat and blood sugar. More studies are needed to  confirm the effects of these drugs on oral contraceptives,  though, so some experts, including regulators in the  UK, recommend caution in those seeking to avoid pregnancy.

So, let’s get to some good  news to balance out the bad. Semaglutide is well-known for blood  sugar reduction and weight loss, but it turns out that it may also  help keep certain organs healthy. Like the heart.

People with diabetes  have a higher risk of heart attack, stroke, and other dangerous  cardiovascular events, and semaglutide has been known to have a  protective effect against them. But it can also help people without diabetes. One major trial of over 17 thousand  patients with existing heart disease and higher body fat  found that those taking the drug had a lower incidence of acutely life-threatening heart problems compared to those on a placebo.

That one was funded by the  drug company, so grain of salt. In 2024, the FDA approved Wegovy to reduce the risk of these heart problems  in people who may not be diabetic, but do have other risk factors. Researchers are still unraveling  how semaglutide does this.

It could largely be a result of  blood sugar control, or weight loss – including the reduction of  fat around the heart itself – and associated health benefits. Scientists are also looking  into how the drug may protect the heart beyond just blood sugar and weight loss. For instance, GLP-1s seem to  lower molecules associated with inflammation, which is known to  increase cardiovascular risk.

And also a bunch of other risks. It’s also a bunch of– It’s like cancer… Heart disease. Those are the big ones.

But they’re the two big ones. Evidence from mouse studies suggests that it may also reduce what’s called heart remodeling. This is basically structural  changes to the heart’s muscle and blood vessel tissue in  response to cumulative damage, which leads to an enlarged heart.

An enlarged heart is essentially  overcompensating for its inefficiency, also contributing to cardiovascular risk. And then there are potential perks for the brain. Semaglutide seems to improve cognition, protect against nerve-related  disorders associated with diabetes, and protect against Alzheimer’s  and Parkinson’s disease.

Those are two bad ones! No joke – one 2024 study found a  40 to 70% decrease in risk for a first-time Alzheimer’s disease diagnosis  in patients with type 2 diabetes taking semaglutide, compared  to other diabetes meds. Again, scientists suspect that several physiological mechanisms are  likely at play in the brain.

Like in the heart, protection against inflammation in the brain probably plays a role. Evidence also suggests that the drug may improve the function of synapses, which are the structures located between neurons that enable the  transmission of cell signals. Early days for this research,  but fantastic if true.

Like, we did not mean to  make an Alzheimers drug here, but we may have! For another potential undesirable  effect, a large 2024 trial showed that patients on semaglutide  are at higher risk of developing irreversible blindness in one  eye due to a halt in blood flow to the optic nerve, again  compared to other treatments. Now, the overall risk of this condition is low.

The study also didn’t present  evidence to show a causal link – just a correlation between the use of semaglutide and the increased risk. In addition, some studies suggest that semaglutide increases the risk of diabetic retinopathy. This is a disease of the retina  that can develop in patients with diabetes due to cumulative damage  to blood vessels inside the eyes.

Scientists have observed that  the disease is more likely in semaglutide users who experience  more rapid drops in blood sugar. There is a noted phenomenon  in which this eye condition paradoxically worsens when  blood sugar drops quickly, before potentially getting better. So, vision problems are another  case of weighing the risks of taking semaglutide with  the risk of not taking it, and that varies widely from person to person.

So, we’ve talked about  semaglutide’s effect on blood, stomach and GI tract, other organs, and eyes. It turns out that semaglutide may directly or indirectly affect your bones. Some studies suggest it could help protect joints and increase bone cell growth.

There’s conflicting evidence here—other  studies suggest that it could also increase bone loss in certain  populations, especially older adults. And that could be because bones are always undergoing a natural  push-and-pull, with gain and loss of bone tissue happening  in balance with each other. So that balance could be thrown out of whack.

Here, too, ensuring adequate  nutrition and exercise to maintain bone-supporting  muscle mass can help keep bones as healthy as possible  while taking the drug. Wildly enough, we could keep  going, but as is often the case, we’ve had to boil this down to an abridged list of effects of semaglutide. All in all, semaglutide is a super powerful drug, and power comes with risk.

Like practically any other drug…  or like other life choices, there’s a lot to understand about  semaglutide’s risks and benefits. It comes down to weighing these pros and cons with the guidance of a dedicated care team and based on each individual’s  needs and health profile. Ideally, each patient should be empowered with access to nutrition, physical activity, and dedicated doctors to maximize good effects and minimize the not-so-good. [♪OUTRO]