Beauty Review · Eyelash Serums
With over 9.7 million bottles sold and the title of #1 Premium Lash Serum Brand in the U.S., Rodan + Fields Lash Boost is hard to ignore. But does it actually deliver? Here’s an honest breakdown of the ingredients, results, safety concerns, and how it compares to the competition.
What Is Lash Boost?
Lash Boost is a nightly eyelash conditioning serum developed by dermatologists Dr. Katie Rodan and Dr. Kathy Fields — the same founders behind Proactiv. Applied once every evening along the upper lash line, it conditions lash fibers while key actives enhance the visible appearance of length, volume, and definition. It also works on brows.
Unlike prescription lash treatments like Latisse, Lash Boost is a cosmetic serum — it enhances the appearance of lashes rather than clinically altering their growth cycle. In 8-week clinical testing, over 85–90% of users reported fuller and longer-looking lashes.


Key Ingredients
The formula is more complete than most competitors. Here’s what’s inside and why it matters:
01 Isopropyl Cloprostenate
A synthetic prostaglandin analog — the main active responsible for enhancing visible lash length and density. The same class of ingredient used in prescription lash treatments, at a cosmetic concentration. This drives the most noticeable results.
02 Keratin & Hydrolyzed Keratin
The structural protein that makes up natural lash fibers. Topical keratin coats and strengthens lashes, reducing brittleness and breakage.
03 Biotin + Panthenol
Vitamin B7 and Pro-Vitamin B5 work together to condition lash and brow fibers, supporting a thicker, healthier-looking appearance over time.
04 Sodium Hyaluronate + Copper Tripeptide-1
Hyaluronate draws moisture into lash fibers to minimize breakage; Copper Tripeptide-1 is a bioactive peptide with well-documented research on follicle health.
Lash Boost contains isopropyl cloprostenate, a prostaglandin analog. It’s responsible for the most visible results — but also the ingredient with the highest sensitivity risk. Read the safety section before purchasing.
Results: What to Expect
Most users follow a predictable timeline based on 8-week US clinical testing and thousands of verified reviews:
Week 1–2 Conditioning phase
Lashes feel softer and more hydrated. No visible length change yet — the serum is prepping lash fibers and follicles. Consistency here is key.
Week 4 First visible changes
Most users notice lashes appearing slightly longer at the tips. Some report darker, more defined lashes even without mascara.
Week 8 Full clinical results
The benchmark point. Over 85–90% of users reported visibly fuller, longer lashes. Brow users also reported visible density improvement.
Month 3+ Maintenance
Many long-term users reduce to a few applications per week once desired results are achieved. One 5ml bottle lasts approximately 90 days at daily use.
“3 months of using this every night. I went from having short straight lashes to luscious long curled lashes.” — Ari, 5★
How to Use It
- Remove all makeup and cleanse your face. Lashes must be clean and fully dry.
- Dip the brush once per eye — wipe off excess on the bottle rim.
- Apply to the upper lash line only, like a liquid eyeliner stroke. Not the lower lash line.
- Wipe off any excess that spreads onto the eyelid with a clean fingertip.
- Wait 90 seconds for the serum to dry before lying down.
- Apply to brows after lashes for fuller-looking results.
- Do not wash your face after. This is the last step of your PM routine.
Side Effects & Safety
Lash Boost is well tolerated by the majority of users, but because it contains a prostaglandin analog, it’s important to be informed before starting.
Some users have reported the following, especially in the first weeks of use:
- Eye redness or itchiness
- Dry or watery eyes
- Temporary eyelid darkening
- Eye sensitivity or eyelid inflammation
- In rare cases, styes or iris color change with prolonged use
Do not use if you are: pregnant or nursing · undergoing treatment for glaucoma or cancer · prone to conjunctivitis, styes, or dry eyes · allergic to tree nuts (contains sweet almond extract).
Lash Boost has been found safe and non-irritating for contact lens wearers. Allow the serum to dry fully before inserting lenses.
How It Compares
Side-by-side with two other popular lash serums available at Dermluxa:
| Feature | R+F Lash Boost | GrandeLASH-MD | RevitaLash |
|---|---|---|---|
| Prostaglandin Analog | ✓ Yes | ✓ Yes | ✗ No |
| Results by | 4–6 weeks | 4–6 weeks | 6–8 weeks |
| Works on Brows | ✓ | ✓ | ✓ |
| Paraben-Free | ✓ | ✓ | ✓ |
| Price | $108.50 | $28–$100 | $98–$150 |
Both R+F Lash Boost and GrandeLASH-MD are available at Dermluxa. If you’d prefer to avoid a prostaglandin analog, GrandeLASH-MD starts from $28.80.
Yes — for most users. In 8-week clinical testing, 85–90% reported visibly fuller and longer-looking lashes. Results depend on consistent nightly use; most see early changes by week 4.
Yes. Apply with the same precision brush along the brow line after your lash application. Don’t wash your face after applying to brows.
One 5ml bottle lasts approximately 90 days with once-nightly use. Many long-term users extend this to 4–5 months by reducing to a few applications per week once results are maintained.
The most common are temporary eye redness, mild itchiness, and occasional eyelid darkening — usually in the first 1–2 weeks. These are linked to the prostaglandin analog. If irritation persists, discontinue and consult a physician.
The Bottom Line
Rodan + Fields Lash Boost is one of the most clinically tested lash serums available without a prescription. For most users, it delivers visibly fuller, longer lashes within 4–8 weeks of consistent nightly use. The formula — combining a prostaglandin analog with keratin, biotin, and conditioning peptides — is more complete than most at this price. The main caveat is the prostaglandin ingredient, which warrants attention for sensitive-eyed users. At $108.50 for a 90-day supply, it’s a well-justified investment if you’re prepared for nightly consistency.

