Byrdie's Top Eyelash Growth Serum Is RapidLash – What It Costs
Byrdie's Best Overall, RapidLash Eyelash Enhancing Serum, lists at $35 on Amazon. The results windows in these sources run from 6 to 12 weeks, so a serum judged before week 6 hasn't had the time any of them describe.
At $35 on Amazon, RapidLash is the cheapest of the top three picks in Byrdie’s Apr 16, 2026 update. Then plan on 6 to 12 weeks, the window the reviews behind these picks describe. A bottle judged at week two has had only a third of the shortest run.
Whichever top eyelash growth serum you choose, read its label before you pay, then give it the full window before you decide.
Byrdie’s Top Pick Costs $35; Its No-Prostaglandin Pick Costs $17 More
Each rank below is the reviewer’s own, as the “Ranked by” column shows. Byrdie’s prices are its Amazon listings as of its Apr 16, 2026 update. The Lash List’s price is as of its June 9, 2026 update.
Glamour’s price is as shown on its page, so check it before you buy. Price per mL appears only where a page gives the size. The last column shows whether a source names a prostaglandin analogue, and the ingredient section below explains why that matters.
| Pick | Ranked by | Listed price | Price per mL | Prostaglandin analogue? |
|---|---|---|---|---|
| RapidLash Eyelash Enhancing Serum | Byrdie, Best Overall | $35 (Amazon) | Size not listed | Unconfirmed; read the label |
| Babe Original Essential Lash Serum | Byrdie, runner-up | $49 (Amazon) | Size not listed | Unconfirmed; read the label |
| Benefit Cosmetics Whoop Lash | Byrdie, Best Without Prostaglandin | $52 (Amazon) | Size not listed | No, per Byrdie’s category |
| SOWN Root 1 | The Lash List, 1st of 14 | $58 for 3 mL | $19.33 | No: “Prostaglandin-Free,” per The Lash List |
| RevitaLash Advanced Eyelash Conditioner | Glamour, Best Overall | $59 for 3.5 mL | $16.86 | Yes: cloprostenol ethyl amide, per Glamour |
The gaps: Babe costs $49 − $35 = $14 more than RapidLash, and Whoop Lash costs $52 − $35 = $17 more.
Verdict: RapidLash suits a buyer who wants Byrdie’s first-place pick, and it is the cheapest of Byrdie’s top three.
The flaw, and its fix: RapidLash is not Byrdie’s pick for avoiding prostaglandin analogues; that slot went to Whoop Lash. If you want to avoid them, Byrdie’s ranking alone can’t tell you whether RapidLash fits. Fix: read the full ingredient list on the box or the brand’s product page before you pay, or buy Whoop Lash instead.
Strengths: It ranked first after Byrdie’s 12-week trial, and it costs $14 to $17 less than the other two in Byrdie’s top three. Byrdie’s Best Affordable pick, Viebeauti Lash Growth Serum, is cheaper at $22, so RapidLash is not the cheapest of the 7 serums Byrdie ranks.
Who should skip → buy: If you want to avoid prostaglandin analogues, buy Whoop Lash, Byrdie’s Best Without Prostaglandin pick at $52, or Root 1, which The Lash List labels “Prostaglandin-Free” at $58.
The other four, each with one strength, one drawback and its fix:
- Babe: Byrdie says it gave “dramatic results.” It costs $14 more than RapidLash, and its prostaglandin status is unconfirmed; read its ingredient list before you pay.
- Whoop Lash: It is Byrdie’s no-prostaglandin pick. At $52 it is the priciest of Byrdie’s top three, and Byrdie’s list gives no size. Read the size on the box to compare its cost per mL with Root 1’s $19.33.
- Root 1: First of 14 on The Lash List, which labels it “Prostaglandin-Free.” At $19.33 per mL it costs more per mL than RevitaLash; what the extra buys is a formula without a prostaglandin analogue.
- RevitaLash: Glamour’s Best Overall, with the lower per-mL cost of the two with a stated size. Its $59 sticker price is the highest in the table, and Glamour lists a prostaglandin analogue in it; Root 1 is the prostaglandin-free choice with a stated size.
An Ophthalmologist Says Serums Condition Lashes Against Breakage
The plainest expert answer here comes from Diane Hilal-Campo, MD, a board-certified ophthalmologist (eye doctor). She told Glamour that these formulas “hydrate, condition, and fortify lashes to help prevent breakage and support longer growth before they shed.”
In plain words, a serum helps the lashes you already have stay in better shape for longer. It is a claim about how lashes look and hold up. It doesn’t promise new lashes.
Review sites report what they saw. The Lash List says SOWN Root 1, a “peptide and botanical blend (red clover, biotin),” gave longer, fuller lashes within 6 weeks. Read that as one reviewer’s report on one product.
Prostaglandin or Peptide: Only the Ingredient List Tells You
Two kinds of serum show up on these lists. Prostaglandin analogues are lab-made versions of hormone-like compounds the body makes. Peptide serums use short chains of amino acids instead.
The check matters because of side effects. The Lash List names iris color change, fat loss around the eye and eyelid darkening among the side effects linked to prostaglandin analogues. You want to know which kind you’re buying before the first dose.
The check is also harder than it looks. The Lash List counts more than 15 names these ingredients go by, so skimming for one word can miss one. Glamour lists RevitaLash’s as cloprostenol ethyl amide, a name without the word “prostaglandin” in it.
Read the full list on the box or the brand’s own product page, then read the brand’s warning text next to it.
Results Windows Run From 6 to 12 Weeks Across These Sources
No single page lines these windows up. Side by side, they give you two checkpoints.
- Week 0, before the first dose. Read the ingredient list for a prostaglandin analogue. Photograph your bare lashes in the light you’ll use again later.
- Before week 6, the quiet stretch. The earliest window in these sources is 6 weeks, so seeing no change yet doesn’t mean the serum has failed.
- Week 6, first checkpoint. The Lash List reports longer, fuller lashes from Root 1 within 6 weeks, and Glamour gives 6 weeks for a first visible change from RevitaLash. Compare against your week-0 photo.
- Week 12, second checkpoint. Byrdie used its serums for 12 weeks before ranking them, and Glamour gives 12 weeks for RevitaLash’s length and volume. No source here describes a longer window.
- The 18-month figure is not a results window. It is how long The Lash List’s whole review of 14 serums ran, not how long one serum takes.
- Any week, watch the eye area. Redness or irritation is the kind of reaction the FDA calls especially troublesome near the eyes.
Eyelids Are Delicate, the FDA Warns
The FDA reminds readers that eyelids are delicate and that an allergic reaction or irritation in the eye area “can be particularly troublesome.” That warning covers the whole eye area, not one ingredient type.
So a peptide-only label doesn’t mean you won’t react. If an ingredient has bothered your eyes in another product, the ingredient list is where you’ll spot it again.
A “Restore Growth” Claim Can Make a Serum a Drug, per the FDA
The FDA lists claims that a product will “restore hair growth” as the kind that can make it a drug, even when it’s sold as a cosmetic.
That makes the wording on the box worth reading. A serum sold as a cosmetic that promises to restore growth is making the kind of claim the FDA links to drugs. For how this shows up on real boxes, see what lash serum labels can claim.
Next step: If a label shows a prostaglandin analogue and you want to weigh it against Latisse, read Latisse vs over-the-counter lash serums.
Related reading: Babe Original Lash Serum Contains a Prostaglandin.
FAQ
Can a Lash Serum Show Results in a Week?
None of these sources describes a result that fast. The earliest window is 6 weeks, per The Lash List and Glamour.
Which Pick on Byrdie’s List Has No Prostaglandin?
Benefit Cosmetics Whoop Lash, Byrdie’s Best Without Prostaglandin pick at $52 on Amazon.
Is SOWN Root 1 a Peptide Serum?
The Lash List calls it a peptide and botanical blend with red clover and biotin. Check the box for the full list.
Can a Lash Serum Claim to Restore Growth?
The FDA says a claim that a product will restore hair growth can make it a drug, even if it’s sold as a cosmetic.
This article is general information, not medical advice. For questions about your eyes or lashes, ask a doctor.
