Understanding Latisse and Its Purpose
Latisse is the brand name for a prescription ophthalmic solution containing the active ingredient bimatoprost [1.7.3]. It is the only treatment approved by the U.S. Food and Drug Administration (FDA) specifically for treating hypotrichosis, which is the condition of having inadequate or not enough eyelashes [1.7.1, 1.7.3]. Originally, bimatoprost was used in a medication called Lumigan to treat high intraocular pressure (glaucoma), where eyelash growth was a noted side effect [1.3.5]. This led to its development as a cosmetic treatment to grow eyelashes longer, fuller, and darker [1.6.4].
How Does Latisse Work?
The hair on your body, including your eyelashes, goes through a growth cycle with several phases [1.5.1]. The active growth phase is called the anagen phase. Latisse works by extending the duration of this anagen phase and increasing the number of hairs that are in this phase at any given time [1.6.4]. This allows your eyelashes to grow longer and thicker than they would naturally [1.6.2].
To achieve full results, it's recommended to apply Latisse to the base of the upper eyelashes daily for 16 weeks [1.2.1]. You may start to see results in as little as four weeks, with peak results appearing at the 16-week mark [1.2.1, 1.2.4].
Long-Term Safety and Continued Use
Clinical studies have shown that daily application of Latisse over a one-year period is safe and well-tolerated [1.4.1]. The key to long-term use is that it remains effective for as long as you use it as prescribed [1.2.2].
After the initial 16-week daily application period, you should consult with your doctor about a maintenance plan [1.2.1]. Many users can reduce the application frequency to every other day, or even a few times a week, to maintain their results [1.2.2, 1.5.5]. This helps extend the life of each bottle and reduces the ongoing cost [1.2.3].
If you stop using Latisse completely, your eyelashes will gradually return to their previous appearance [1.5.2]. This reversal process happens over several weeks to months as your lashes complete their growth cycle [1.2.2]. The results are not permanent, and continued use is necessary for maintenance.
Potential Long-Term Side Effects
While generally safe, long-term use of Latisse carries some potential side effects. The most common side effects, occurring in less than 4% of patients, include eye itching, eye redness, dry eyes, and eyelid irritation [1.4.2, 1.3.3].
Other less common, but more significant, potential side effects include:
- Eyelid Skin Darkening (Hyperpigmentation): The skin where Latisse is applied may darken due to an increase in melanin [1.3.2]. This effect is usually reversible and is expected to fade over several weeks or months after discontinuing the product [1.5.2, 1.10.2].
- Permanent Iris Color Change: Bimatoprost can cause the colored part of the eye (the iris) to become browner. This change occurs slowly, sometimes over months or years, and is likely to be permanent [1.3.1, 1.8.2]. The risk is higher for those with hazel or green eyes [1.8.1].
- Periorbital Fat Loss: There have been reports of prostaglandin analogues (the class of drugs bimatoprost belongs to) causing a loss of fat around the eye, which can lead to a sunken or hollowed appearance [1.3.3, 1.9.1]. While this is a documented side effect for glaucoma eye drops placed directly in the eye, it is considered rare for Latisse when applied correctly to the eyelid margin [1.9.1, 1.9.3]. In many cases, this effect may be reversible upon stopping the medication [1.9.1].
- Hair Growth Outside Treatment Area: If the solution frequently touches other areas of the skin, it can cause unwanted hair growth [1.3.2]. It is important to blot away any excess solution to prevent this [1.2.5].
Latisse vs. Over-the-Counter (OTC) Serums
A key distinction between Latisse and OTC eyelash serums is the active ingredient and FDA approval [1.6.1].
| Feature | Latisse | Over-the-Counter (OTC) Serums |
|---|---|---|
| Active Ingredient | Bimatoprost (a prostaglandin analog) [1.6.2] | Peptides, biotin, botanical extracts [1.6.3] |
| Mechanism | Extends the lash growth (anagen) phase [1.6.4] | Condition, strengthen, and hydrate existing lashes [1.6.1] |
| FDA Approval | Yes, FDA-approved to grow eyelashes [1.7.1] | No, not approved by the FDA for lash growth; considered cosmetics [1.6.2, 1.6.3] |
| Availability | Prescription only [1.7.2] | Available over the counter [1.6.1] |
| Proven Efficacy | Clinically proven to increase lash length, thickness, and darkness [1.6.4] | Lacks extensive scientific evidence for lash growth, though may improve appearance [1.6.3] |
Conclusion
Latisse can be used safely for long periods—essentially, for as long as you wish to maintain the results of longer, fuller, and darker eyelashes. After an initial 16-week daily treatment phase, a maintenance schedule of less frequent applications is typically adopted under a doctor's guidance [1.2.1, 1.5.5]. While effective, users should be aware of potential side effects, such as reversible eyelid skin darkening and the rare but likely permanent change in iris color [1.10.2, 1.8.2]. If you stop using the product, your eyelashes will return to their previous state [1.5.2]. Consulting with a healthcare provider is essential to determine if Latisse is appropriate for you and to monitor for any side effects during long-term use.
For more information from the manufacturer, you can visit the official Latisse® Professional website.
