Lumigan and latanoprost are not the same medication. Lumigan is the brand name for bimatoprost, a different drug from latanoprost (sold as Xalatan). Both are prescription eye drops used to lower eye pressure in people with glaucoma or ocular hypertension, and they work in similar ways, but they differ in their chemical makeup, side effect profiles, cost, and even storage requirements.
Two Different Drugs in the Same Class
Bimatoprost (Lumigan) and latanoprost (Xalatan) both belong to the prostaglandin analog class of glaucoma medications. They lower eye pressure by helping fluid drain out of the eye more efficiently, primarily through a drainage route behind the iris called the uveoscleral pathway. Neither drug reduces how much fluid the eye produces. Instead, they both work by loosening up the tissue along the drainage pathways, making it easier for fluid to pass through.
There has been some scientific debate about whether bimatoprost should be classified separately as a “prostamide” rather than a prostaglandin analog. However, research has shown that bimatoprost activates the same receptor as latanoprost and behaves as a prostaglandin analog in practice, though it penetrates the cornea less efficiently.
How Their Effectiveness Compares
Both drugs are effective at lowering eye pressure, but bimatoprost has a slight edge in clinical trials. A review of head-to-head comparison trials found that in 92% of pressure measurements, patients on bimatoprost had lower average eye pressure than those on latanoprost. The difference between the two ranged from 0 to 1.5 mmHg, which is modest. Bimatoprost also produced higher rates of patients reaching their target pressure levels. That said, the differences were not always statistically significant, and both drugs are considered first-line treatments for glaucoma.
Dosing and Concentration
Both medications are used once daily, typically applied in the evening. Lumigan comes in a 0.01% or 0.03% concentration, while latanoprost is formulated at 0.005%. Despite the different concentrations, each requires just one drop per affected eye per day. There is no meaningful difference in how you use them day to day.
Side Effects: Red Eyes and Eyelash Changes
The most common side effect of both drugs is conjunctival hyperemia, the medical term for red, bloodshot eyes. Bimatoprost tends to cause more redness than latanoprost, which is one reason some doctors start patients on latanoprost first.
Both drugs can cause noticeable eyelash growth. In one direct comparison trial, 13% of patients on bimatoprost experienced eyelash changes compared to 4% on latanoprost. Bimatoprost also tends to trigger eyelash growth sooner. In fact, the eyelash-growing effect of bimatoprost is so reliable that a separate formulation (Latisse) is marketed specifically for that purpose. Studies of latanoprost have reported eyelash thickening in anywhere from 37% to 77% of patients in Japanese populations, suggesting the effect can vary widely depending on the study and the population.
Both drugs can also darken the color of the iris over time, particularly in people with hazel or mixed-color eyes. This change in iris pigmentation can be permanent. People with uniformly blue or brown eyes have a lower risk.
Storage Requirements Differ
One practical difference that matters at home: latanoprost requires refrigeration before you open the bottle. Once opened, it should be stored at or below 25°C (77°F) and used within six weeks. Bimatoprost does not need refrigeration before opening, making it slightly more convenient for travel or for people who might forget to keep their drops cold. After opening, bimatoprost should also be stored at room temperature or below 25°C.
Cost and Generic Options
Generic latanoprost has been available for years and is one of the most affordable glaucoma medications on the market. Generic bimatoprost received FDA approval more recently, with the first generic version approved in March 2025. Even with generics now available, bimatoprost remains significantly more expensive. Generic bimatoprost 0.01% starts around $230 for a 2.5 mL bottle, while generic latanoprost typically costs a fraction of that. For many patients, this price gap is the deciding factor when choosing between the two.
Why Your Doctor Might Choose One Over the Other
If you’re currently on one of these medications and wondering about switching, the decision usually comes down to a few factors: how well your eye pressure is controlled, how much redness or irritation you experience, and cost. Some patients who don’t reach their target pressure on latanoprost are switched to bimatoprost for the slightly greater pressure-lowering effect. Others who experience too much redness on bimatoprost may do better on latanoprost. Neither drug is universally better. They are closely related tools that work through the same biological pathway, but they are distinct medications with their own profiles.