Prescription bimatoprost, sold in the United States as Latisse, is the most effective proven way to grow longer, thicker and darker eyelashes. Apply it once nightly to the upper lash line. Growth is often noticeable after about 8 weeks, with fuller results assessed around 16 weeks. After treatment stops, lash growth gradually returns toward its original level.
For healthier-looking natural lashes, reduce breakage and address any cause of lash loss. Castor oil, trimming and most cosmetic lash serums do not have the same evidence for true eyelash growth as bimatoprost. A 2024 review also found that bimatoprost has the strongest evidence among eyelash-growth products.
Eyelash Growth Options at a Glance
| Goal | Best-supported approach | How quickly it works | Important limitation |
|---|---|---|---|
| Longer, darker, fuller lashes | Prescription bimatoprost | Often noticeable by 8 weeks | Requires medical guidance and consistent use |
| Fewer broken lashes | Gentle makeup removal and less mechanical or chemical stress | Gradual | Prevents damage but does not extend the growth cycle |
| Immediate fuller appearance | Mascara or carefully applied false lashes | Immediately | Cosmetic effect only |
| Sudden or patchy lash loss | Evaluation by a dermatologist or eye-care professional | Depends on the cause | The underlying condition must be treated |
How Does Bimatoprost Grow Eyelashes?
Bimatoprost is a prostaglandin analog that appears to increase the proportion of eyelashes in the active growth phase and lengthen that phase. In a randomized clinical study, bimatoprost increased average eyelash length by 1.4 millimeters after 16 weeks, compared with 0.1 millimeters with the vehicle treatment.
In the same study, 78% of participants using Latisse had at least a one-grade improvement in overall eyelash prominence at week 16. The figure was 18% among participants using the vehicle treatment.
How to Apply Prescription Bimatoprost
Use bimatoprost exactly as prescribed:
- Remove makeup and contact lenses. Clean and dry your face.
- Place one drop on the supplied sterile applicator.
- Apply it along the skin of the upper eyelid margin, at the base of the upper eyelashes.
- Blot away any excess that runs beyond the eyelid.
- Use a new sterile applicator for the other eye.
- Do not apply it to the lower lash line.
- Do not use extra applications. More product does not increase growth.
These instructions come from the Latisse prescribing information. Remove contact lenses before application and replace them according to the product instructions.
What Are the Risks of Bimatoprost?
Bimatoprost can cause itchy eyes, eye redness and darkening of the skin around the eyelids. It can also increase brown pigmentation in the iris, which may be permanent. Other possible effects include unwanted hair growth outside the treatment area and changes in intraocular pressure.
Speak with a healthcare professional before using bimatoprost if you:
- Use glaucoma medication or another prostaglandin eye drop.
- Have a history of eye inflammation or another eye disease.
- Are pregnant, planning pregnancy or breastfeeding.
- Have had an allergic reaction to bimatoprost or any ingredient.
Do not use someone else's prescription or apply glaucoma medication to the lash line without medical advice.
How to Make Eyelashes Look Healthier Naturally
Gentle lash care can reduce breakage and help existing eyelashes remain intact, but it will not make them grow beyond their natural potential.
- Remove mascara gently every night without rubbing or pulling.
- Avoid heated eyelash curlers and limit frequent use of standard curlers.
- Take breaks from lash extensions, lash lifts and heavy false lashes.
- Stop using any product that causes redness, swelling, itching or burning.
- Keep makeup tools clean and replace old eye makeup.
- Avoid pulling, twisting or trimming eyelashes.
- Treat eyelid inflammation, dandruff-like debris or recurrent styes with professional guidance.
Eyelash extensions and chemical lash treatments can irritate the eyelid or damage follicles. Mechanical pulling can also cause traction-related lash loss.
Does Castor Oil Grow Eyelashes?
There is not enough clinical evidence to recommend castor oil as a true eyelash-growth treatment. It may coat and condition existing lashes, making them look shinier or thicker, but evidence that it reliably stimulates longer growth remains largely anecdotal. Castor oil can also irritate the eye if it enters the tear film.
Do not put homemade oils, essential oils or non-sterile products directly into the eye.
Do Over-the-Counter Eyelash Serums Work?
Some over-the-counter serums contain conditioning ingredients such as peptides, panthenol, oils or plant extracts. These ingredients may improve the appearance or flexibility of lash hair, but many have limited clinical evidence for increasing true lash length or density.
The 2024 review found stronger evidence for bimatoprost than for most other serum ingredients. More research is needed on their safety and effectiveness.
Read the ingredient list carefully. Avoid products that do not clearly identify their active ingredients, including products marketed as "prostaglandin-free" without transparent labeling.
When Should You See a Doctor About Eyelash Loss?
See a dermatologist, optometrist or ophthalmologist if eyelash loss is sudden, patchy, occurring in clumps or affecting one eye more than the other. Possible causes include blepharitis, alopecia areata, thyroid disease, skin conditions, medication effects, nutritional deficiencies and irritation from cosmetics or extensions.
Seek prompt eye-care advice if lash loss occurs with:
- Eye pain, redness or discharge.
- Eyelid swelling or persistent itching.
- Blurred vision or light sensitivity.
- A gritty sensation.
- Lashes turning inward and rubbing the eye.
- Loss of eyebrows or scalp hair at the same time.
Treating the cause is more important than applying another growth serum. Non-scarring eyelash loss may improve after the trigger is addressed, while follicle scarring can make regrowth difficult or permanent.
Bottom Line
Choose the approach that matches the problem. Use mascara or false lashes for an immediate cosmetic change, gentle care to limit breakage, and professional evaluation for sudden or uneven loss. Bimatoprost requires a prescription and medical guidance because it can affect the eyes and surrounding skin.