5 Lumigan (Bimatoprost) Side Effects You Should Know About

Bimatoprost (Lumigan) is a first-choice medication for treating glaucoma. It also treats high pressure inside the eye (ocular hypertension). Bimatoprost works well to lower eye pressure and is quite safe. Using bimatoprost every day can help prevent vision loss due to these conditions.

Bimatoprost works by acting like the body’s natural prostaglandins. Prostaglandins are chemicals that, among many other functions, help drain fluid from inside the eye. When there’s less fluid, eye pressure goes down.

Many people end up using bimatoprost for many years with minimal problems. But as with all medications, side effects are possible. Let’s review five bimatoprost side effects you should look out for.

1. Red eyes

Red eyes is the most common side effect of bimatoprost eye drops. In one of bimatoprost’s clinical trials, it happened in close to 1 out of 3 people who used it. Some studies suggest it may be even more common than this. Red eyes are more likely to happen if you use the higher strength (0.03%) of bimatoprost.

This redness is likely due to widened blood vessels, not inflammation (swelling). It’s usually mild and appears soon after the first dose. It typically goes away within about a month. If you’re still experiencing bothersome redness after that point, let your healthcare provider know.

Most other glaucoma eye drops can also cause this side effect, but less often than bimatoprost. Examples include:

• Latanoprost (Xalatan, Xelpros)

• Timolol (Timoptic, Timoptic-XE, Timoptic in Ocudose, Istalol, Betimol)

• Brimonidine (Alphagan P, Qoliana)

• Brinzolamide (Azopt)

You’ve likely seen or heard of over-the-counter (OTC) eye drops that treat red eyes. Clear Eyes or Visine are two popular examples. Some of these redness-relieving medications can raise pressure in the eye. This means they may not be safe to use if you have a certain type of glaucoma or issues with eye pressure. Talk to your healthcare provider before using other medications to treat red eyes.

2. Itchy eyes

Itchiness is another possible bimatoprost side effect. It’s usually manageable and unlikely to force you to stop taking this medication. Itchiness can also happen with other glaucoma eye drops.

Try not to rub your eyes if they’re itchy. Rubbing can actually make it feel worse. Cold compresses can be a quick and safe way to relieve itching. Take a clean, wet washcloth and gently place it over your eyes with your eyes closed. You may want to avoid using food items from the refrigerator or freezer, like frozen peas. These could be contaminated with bacteria and cause an eye infection.

There are various OTC medications that can help with itchy eyes. Some may be safer for you than others depending on your health conditions or other medications you may take. Again, talk to your healthcare provider or pharmacist before using other medications to treat the itching.

3. Other eye irritation

Redness or itching are more common types of eye irritation from bimatoprost. But you may also experience dryness, burning, or feeling like there’s something in your eyes. Some eye drops, such as artificial tears, can hydrate your eyes to help them feel better. Remember to talk to your healthcare provider about whether eye drops would be helpful for you.

Allergies to bimatoprost or other glaucoma eye drops are rare. But the preservatives in these medications are a common cause of eye irritation. These additives prevent bacteria and other germs from contaminating the medicine. But some people have trouble tolerating them.

Some forms of bimatoprost contain benzalkonium chloride (BAK). BAK is a preservative that often causes irritation. Currently, all forms of bimatoprost eye drops contain this ingredient. If your healthcare provider determines you should avoid BAK, they may recommend alternatives. BAK-free options that work similarly to bimatoprost include travoprost (Travatan Z) and tafluprost (Zioptan).

4. Eyelash growth

Bimatoprost can make you grow more eyelashes. It can also make your eyelashes longer and thicker. This is because bimatoprost works like a certain prostaglandin, which is thought to boost hair growth as well.

This side effect doesn’t typically cause discomfort. But it can change how you look. Some people want fuller eyelashes and may like this side effect. In fact, there’s a different form of bimatoprost, called Latisse, that’s FDA approved to promote eyelash growth.

The eyelash effect is not permanent. If you stop using bimatoprost, expect your eyelashes to eventually return to how they were before starting this medication.

5. Darker eyes, eyelids, or eyelashes

Bimatoprost causes your cells to make more melanin. Melanin is the natural chemical that causes the brown color in skin and hair. This is also due to the prostaglandin-like effect of bimatoprost.

Your iris (the colored part of your eye), eyelids, and/or eyelashes may look darker than normal after starting bimatoprost. Changes in eye color don’t usually appear right away. This may happen after months or years of taking bimatoprost.

This bimatoprost side effect is not very common. But it’s important to know that darker eye color can be permanent, even after stopping bimatoprost. Darker eyelids and eyelashes usually go away after stopping it.

It’s unlikely that these color changes would cause long-term problems. But some people may not like this change in appearance. Your healthcare provider will monitor these changes down the line. But let them know if you notice this side effect and find it bothersome.

When should I contact my healthcare provider about bimatoprost side effects?

Contact your healthcare provider if redness, itching, or other irritation are severe. You should also reach out if these bimatoprost side effects don’t get better after a few weeks. Your healthcare provider can help figure out if it’s due to other causes.

You should also contact your healthcare provider if you notice more severe symptoms. A couple red flags to look out for:

• Blurry or worse vision: This can be a sign of eye inflammation. It’s more likely to happen if you already have another eye inflammation condition, such as iritis. Vision changes can also be a sign of fluid build-up in the macula (macular edema). Your risk of getting macular edema from bimatoprost is higher if the lens of your eye is damaged or missing (like after cataract surgery).

• Pus, crusting, or swelling around your eye: This can be a sign of infection, such as pink eye (conjunctivitis). Infection typically happens if your bottle of bimatoprost gets contaminated with bacteria. Remember to wash your hands before each use. Be careful not to touch the dropper tip with your eye, hands, or any other surface.

Changes in eyelashes and eye or eyelid color aren’t serious health problems. But it affects your appearance. And it’s OK if you don’t like these changes. If these effects concern you, talk to your healthcare provider about switching to a different medication. Keep in mind that eyelash and color changes can also happen with other prostaglandin eye drops, like latanoprost.

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Written by:

Aileen Chu, PharmD, BCPS

Aileen Chu, PharmD, has over 8 years of experience working as a clinical pharmacist in the emergency department, where she sees the consequences of people not being empowered to take their medications correctly. This experience has made her especially passionate about helping patients understand their medications and ensuring that medications are affordable and accessible.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

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