Key takeaways:
Gemtesa (vibegron) is a prescription medication that treats overactive bladder (OAB) in adults. It comes as an oral tablet.
Gemtesa is well tolerated by most people who take it. But it may still cause side effects. Some, such as headaches and diarrhea, are generally mild and can be managed with home remedies. Others, such as urinary retention, may warrant medical attention.
Understanding what to expect and how to handle Gemtesa side effects can help you feel more in command of your OAB treatment. Thankfully, these side effects are typically temporary and should improve as your body gets used to the medication.
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Gemtesa (vibegron) is a prescription medication that helps lessen symptoms of overactive bladder (OAB) in adults. It’s an oral tablet that works by relaxing your bladder muscles. As a result, you should feel less urgent needs to pee and experience fewer accidents and leaks. You also shouldn’t have to urinate as frequently throughout the day.
Gemtesa is well tolerated overall. But, like with any medication, Gemtesa can cause side effects. Understanding these side effects — and how to respond to them — is beneficial for finding success with this OAB treatment.
Gemtesa side effects at a glance
Most of what we know about Gemtesa’s side effects come from clinical trials. The most common and/or mild side effects seen in those trials include:
Headaches
Diarrhea
Constipation
Nausea
Urinary tract infections (UTIs)
Dry mouth
Skin rashes
Rare but potentially serious Gemtesa risks include hot flashes, allergic reactions, and urinary retention.
Here, we’ll dive deeper into seven notable Gemtesa side effects and practical tips for managing them.
1. Headaches
Headaches are one of the most commonly reported side effects of Gemtesa. They tend to be mild to moderate in how they feel.
Headaches should gradually improve with time. But there are still ways to manage them. These headache remedies offer relief for many people:
Trying an over-the-counter (OTC) pain reliever, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin)
Staying hydrated, as dehydration can make headaches worse
Trying stress reduction techniques, such as deep breathing and gentle yoga
Call your primary care provider if your headaches don’t go away or worsen at any point. They can help you figure out the cause(s) of your headaches and if any adjustments to your Gemtesa prescription are necessary.
2. Upper respiratory tract infections
Gemtesa may cause URTIs. Symptoms generally resemble those of the common cold, such as runny nose, sore throat, or mild congestion.
These symptoms are typically mild and should resolve within a few days. To manage these symptoms in the meantime, consider:
Doing your best to rest to allow your body to recover
Staying hydrated with fluids like water and herbal teas
Using OTC cold remedies, such as decongestants or antihistamines, for temporary relief
Turning on a humidifier to further ease congestion and a sore throat
Seeking help for overactive bladder (OAB): Pharmacists outline the different medications that help lessen OAB symptoms.
Your road to bladder control: Learn how Gemtesa works and when your bladder control should start improving.
OAB medication showdown: Compare Myrbetriq (mirabegron) and oxybutynin effectiveness, side effects, and more to see which might work better for your OAB symptoms.
Tips like these can help make your symptoms more manageable. But make sure to call your primary care provider if your cold symptoms extend beyond a few days. They can tell you if another treatment, such as an antiviral or antibiotic, is necessary.
3. Diarrhea
Diarrhea is another relatively common side effect of Gemtesa. This is related to how Gemtesa affects the bladder and other muscles in the digestive tract.
Priority number one with managing diarrhea is staying hydrated — especially if it’s persistent. Without doing so, you may experience significant fluid loss, dehydration, and/or electrolyte imbalances. Make sure to drink fluids such as water, clear broths, or oral rehydration solutions throughout the day.
Eating bland, easy-to-digest foods — such as rice, bananas, toast, and applesauce — can also help soothe your stomach while your symptoms are active. Avoiding high-fat, spicy, or greasy foods is also beneficial. These can irritate the stomach lining and worsen diarrhea. OTC antidiarrheals, such as loperamide (Imodium A-D), can help with diarrhea too, but it's best to check with your primary care provider before trying one. They can tell you if they’re safe for you to take.
If your diarrhea worsens at any point, lasts more than a few days, or you experience concurrent symptoms like fever or dizziness, contact your primary care provider right away. A more serious situation may be underway.
4. Nausea
Nausea is another side effect that some people experience while taking Gemtesa. This feeling can range from mild discomfort to intense queasiness. But, again, it’s generally temporary.
If you’re feeling nauseated, strategies to alleviate your symptoms are quite similar to those used for managing diarrhea:
Eating smaller meals throughout the day rather than three larger meals
Sticking to bland and non-greasy foods that are gentle on the stomach, such as crackers, toast, plain chicken, or rice
Sipping on ginger and peppermint teas that have natural soothing properties
Avoiding foods with strong, off-putting smells or flavors
Affordable OTC and prescription anti-nausea medicines can help manage nausea too. It's best to talk to your primary care provider before taking one, though, to make sure it’d be beneficial for you.
5. Dry mouth
Gemtesa may occasionally cause dry mouth. This is because it can affect the salivary glands, reducing saliva production. However, this side effect tends to be less problematic with Gemtesa compared to other OAB treatments — especially anticholinergics like oxybutynin.
Still, this side effect can be uncomfortable and affect eating, speaking, and oral hygiene. Sipping water regularly during the day is a simple-yet-effective way to moisten your mouth. Sucking on candies or chewing gum (sugar-free) can help increase saliva production. In more severe cases, OTC saliva substitutes or oral moisturizing gels can provide additional relief.
If dry mouth becomes very bothersome, loop in your primary care provider. They might suggest reducing your Gemtesa dosage or switching to an alternative OAB medication, such as Myrbetriq (mirabegron).
6. Hot flashes
Cases of hot flashes have been reported with Gemtesa, but it’s rare. You may have sudden feelings of warmth, sweating, or skin redness, which can be uncomfortable.
Simple tips can help manage hot flashes. For instance, wearing lightweight and breathable clothing can go a long way. Fans and ice packs can also help you stay cool. Drinking cold fluids, such as iced water or chilled herbal teas, can also help lower your body temperature. What’s more, practicing mindfulness, meditation, or yoga can help lower stress — a common trigger of hot flashes.
Talk to your primary care provider if you’re experiencing frequent or intense hot flashes. They might adjust your Gemtesa dosage or explore alternative OAB treatments with you.
7. Urinary retention
Urinary retention is a more serious side effect of Gemtesa. This is a condition that makes it difficult to urinate or creates the sensation that your bladder isn't fully emptying.
It’s crucial to contact your primary care provider right away if you have trouble peeing, have weak urine flow, or still feel like you have a full bladder after peeing. Prolonged urinary retention can lead to UTIs or other complications, such as bladder damage, kidney damage, or urinary incontinence.
Your primary care provider will likely stop your Gemtesa prescription and switch you to another OAB medication if this happens.
How long do Gemtesa side effects last?
Gemtesa side effects can differ for everyone, so it’s difficult to predict how long they’ll last — whether it be days or weeks. They’re generally known to be temporary, though. Talk to your primary care provider if your side effects continue or make you uncomfortable. They can help you figure out the best way to manage them and decide if another OAB treatment may be necessary.
Frequently asked questions
You can take Gemtesa at any time of day, with or without food, as long as you take it at about the same time each day. Many people pick a time they can remember easily, like with breakfast or before bed. Your prescriber may recommend a specific time if you wake up at night often to urinate. If you’re unsure what timing works best with your symptoms or other medications, check with a pharmacist.
Gemtesa isn’t expected to cause weight gain for most people. Still, everyone’s body responds differently. And weight changes can happen for many reasons — including other medications, diet, or potential underlying health conditions. If you notice unexpected weight changes after starting Gemtesa, talk with your prescriber. They can look for other possible causes and decide whether you need any changes to your OAB treatment plan.
Hair loss didn’t appear as a side effect in Gemtesa’s clinical trials. If you notice new or worsening hair thinning or hair loss after starting it, another factor is more likely to blame. Hormonal changes, another medication, or even stress could be the cause. Still, let your prescriber know about any unwanted hair changes you experience. They can help identify the cause and recommend potential next steps.
You can take Gemtesa at any time of day, with or without food, as long as you take it at about the same time each day. Many people pick a time they can remember easily, like with breakfast or before bed. Your prescriber may recommend a specific time if you wake up at night often to urinate. If you’re unsure what timing works best with your symptoms or other medications, check with a pharmacist.
Gemtesa isn’t expected to cause weight gain for most people. Still, everyone’s body responds differently. And weight changes can happen for many reasons — including other medications, diet, or potential underlying health conditions. If you notice unexpected weight changes after starting Gemtesa, talk with your prescriber. They can look for other possible causes and decide whether you need any changes to your OAB treatment plan.
Hair loss didn’t appear as a side effect in Gemtesa’s clinical trials. If you notice new or worsening hair thinning or hair loss after starting it, another factor is more likely to blame. Hormonal changes, another medication, or even stress could be the cause. Still, let your prescriber know about any unwanted hair changes you experience. They can help identify the cause and recommend potential next steps.
The bottom line
Gemtesa (vibegron) is an oral medication that treats overactive bladder. Most Gemtesa side effects are mild and temporary, but they may include diarrhea, headache, and nausea. You can often manage them by drinking plenty of fluids, using over-the-counter pain relievers, or temporarily adjusting your diet. If you have more severe symptoms, such as hot flashes or trouble peeing, it’s a good idea to contact your primary care provider. They can make adjustments to your Gemtesa prescription as needed to ensure it works well and remains safe to use.
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References
Cameron, A. P. et al. (2024). The AUA/SUFU guideline on the diagnosis and treatment of idiopathic overactive bladder. Journal of Urology.
National Institute of Diabetes and Digestive and Kidney Diseases (2019). Definition & facts of urinary retention. National Institutes of Health.
Sumitomo Pharma America. (2025). Gemtesa- vibegron tablet, film coated [package insert].
