Any medication or supplement has the potential to cause side effects, and if you’re considering using Semaglutide or Tirzepatide for weight loss, you definitely need to know what side effects you can expect.
By far, the most common side effect with these medicines is nausea, which is typically mild and can last 24-48 hours after your injection. Since these drugs work partly by slowing down the emptying of the stomach, that means we’ve got partially digested food sitting around in our stomach for longer than we normally would. This by itself can cause some nausea for some patients, but what tends to make matters worse is when we try to eat more food on top of what’s already there in the stomach. We wind up stuffing too much food into an already full stomach, which can really ramp up the nausea. The best way to prevent this side effect is to remember to listen to your body. When you start to feel full, listen to your body, and stop eating. You’ll probably notice that you get full a lot quicker than you did before starting the medicine, and that’s ok! That’s how the medicine works to help you lose weight. It can take a little time to train yourself to adopt new eating habits, but once you get the hang of hearing the messages your body is sending you, it’ll be much easier to avoid that nausea. Eating multiple small meals throughout the day, rather than a few larger meals, can also be a good strategy to avoid overfilling the stomach. Another option to help with nausea is to use an anti-nausea medicine, like Ondansetron (Zofran) or Promethazine (Phenergan). These medicines can be prescribed by your doctor and can often be used as needed if your nausea is really bothersome.
The second most common side effect of Semaglutide and Tirzepatide is constipation. Since we’re slowing things down in the gut, your body has more time to absorb water from your food, which can dry out your stool. And since things aren’t moving through the system as quickly, it’s common to get a little “backed up”. Simple strategies, like eating plenty of fresh fruits and vegetables for natural fiber, and drinking plenty of water every day can help prevent constipation. Another option is to use over the counter Miralax on a daily or as-needed basis to help keep things soft and regular. I recommend Miralax to many of our patients because it’s flavorless, odorless, dissolves in just about any liquid, and works gently without the cramping and urgency caused by other laxatives.
While nausea and constipation are by far the most common side effects we see, you should be aware of some other, more serious potential side effects.
The first is pancreatitis. This is a rare side effect that occurs in less than 1% of patients taking Semaglutide or Tirzepatide. Pancreatitis is caused by inflammation of the pancreas, an organ involved in your digestion, as well as your blood sugar control. Symptoms of pancreatitis can be abdominal pain, nausea, vomiting, fever, and others. If you’re taking Semaglutide or Tirzepatide and think you might be developing pancreatitis, you should contact your doctor right away.
Another rare but potentially serious side effect is gastroparesis. Gastroparesis is paralysis of the stomach. When this occurs, your stomach can’t push food through into the small intestine. This can lead to severe nausea, vomiting, abdominal pain, bloating, and feeling constantly full. Again, this is a rare side effect found in less than 1% of patients, but if you think you might have it, let your doctor know immediately.
It’s also worth mentioning that in animal studies, lab animals that took Tirzepatide or Semaglutide were more likely to develop certain thyroid tumors. We have not seen this in any human trials, but all the same, these medicines are contraindicated (meaning they should not be taken) if you or a family member have a history of Medullary Thyroid Carcinoma or Multiple Endocrine Neoplasia Type 2.
Last, but certainly not least, is the potential for unintended pregnancy! This has been a surprising trend over the past few years as Semaglutide and Tirzepatide have gained popularity, but we have seen a number of cases of unintended pregnancy in women taking these drugs. There are likely two reasons for this- Number one is that these medicines slow down the emptying of the stomach, which can interfere with absorption of oral birth control. It’s recommended that you use a backup form of contraception for at least a month after starting these medicines and after any dosage increase. Number two is that women who were previously infertile due to obesity can lose a significant amount of weight with these drugs, and they may become fertile again! A good rule of thumb is to never assume you can’t get pregnant. If you have a uterus and at least one ovary, consider yourself fertile, and take precautions if you don’t want to get pregnant.
As a bonus, I want to mention that not all side effects are bad. Since more and more research is being done on Semaglutide and Tirzepatide, we’re discovering benefits in numerous other aspects of health, including lower cardiovascular disease risk, treatment of fatty liver disease, reduced joint pain, and even improvements in some mental health problems, like anxiety and stress.
There you have it- The Good, Bad, and Ugly of Tirzepatide and Semaglutide side effects. I hope after reading this that you’ll now be able to make a fully informed decision on whether Semaglutide or Tirzepatide for weight loss is right for you. If you’d like to move forward and kickstart your weight loss journey, and you live in one of our covered states, click here to join our program today! We can’t wait to get you started.
Dr. Kyle Adams, MD
CEO and Medical Director
New Leaf Online
This article is for educational purposes only and is not medical advice. You should always consult your doctor before starting or changing any medications or to discuss any health concerns you may have.
