Kerafen vs PrimeBiome
Data-backed comparison · updated Nov 9, 2026
Winner: Kerafen 🏆
- Kerafen has a higher SiftScore (70.0 vs 62.8).
Side-by-side comparison
| Kerafen | PrimeBiome | |
|---|---|---|
| Price | $79.00 | $79.00 |
| Refund | 60 days | 60 days |
| Type | supplement | supplement |
| Format | Topical Drops | Gummies |
| SiftScore | 70.0 | 62.8 |
| Goals | — | — |
| Best for | Adults comparing a topical nail formula alongside medical advice | Adults comparing skin-support probiotic gummies |
| Pros | 60-day money-back guarantee (return shipping not covered), Topical drop format applied directly to the nail, Names 15 ingredients, including undecylenic acid, tea tree oil and manuka oil, Single bottle available at $79, Page states made in the USA, vegan and free of the top eight allergens | 60-day money-back guarantee, Ten named ingredients, Gummy format with no stimulants, per the page, Two-bottle price published ($158) |
| Cons | No concentrations or percentages are published for any ingredient, No product-specific trial is linked, The VSL claims it "erases fungus in just 60 seconds", which no topical has been shown to do, The 4.94/5 rating is a vendor aggregate of 23,622 reviews with only one named testimonial, Onychomycosis often needs medical treatment; a cosmetic oil is not a cure | Proprietary blend without per-ingredient doses, No CFU count published for Bacillus coagulans, No product-specific clinical trial is linked, Skin-turnover and gut-aging claims are not proven for the formula, The 19,479-review claim is a vendor aggregate |
The short version
Kerafen and PrimeBiome are both published in the Skin & Nails category. Their documented SiftScores are 70.0 and 62.8, a difference of 7.2 points. The verdict above lists the documented reasons: Kerafen has a higher SiftScore (70.0 vs 62.8)..
Price and refund terms
At the documented single-purchase price, Kerafen is $79.00 and PrimeBiome is $79.00. The two prices are identical in our captured data. Refund terms: Kerafen 60-day refund window; PrimeBiome 60-day refund window. A longer window reduces the risk of a failed experiment, but it does not make the formula better. The Value component of the score accounts for both the price relative to the category median and the refund window.
Formula and transparency
Kerafen lists no complete ingredient list in our captured data. PrimeBiome lists 10 named ingredients: Bacillus Coagulans, Babchi, Dandelion, Fennel, Inulin, Fenugreek, Lemon Balm, Organic Ceylon Ginger and 2 more. The two formulas do not share any named ingredients in our data. Only PrimeBiome lists Bacillus Coagulans, Babchi, Dandelion, Fennel, Inulin, Fenugreek. One side publishes no ingredient list at all, so the formula comparison is limited to the documented side; the missing list is a transparency gap, not a neutral tie. Kerafen has no documented red flags in our data. PrimeBiome has 1 documented red flag: exaggerated-claims. Ingredient order and blend totals are not the same as per-serving doses; without a Supplement Facts panel, part of the formula remains unknown. A longer ingredient list is not automatically a better formula; disclosure, dose and evidence quality matter more than the count.
Who should consider Kerafen
Consider Kerafen if the documented profile fits you: the page positions it for Adults comparing a topical nail formula alongside medical advice. It is a topical drops product at $79.00 with 60-day refund window refund terms. This is a fit based on documented attributes, not a claim that it works for your health situation.
Who should consider PrimeBiome
Consider PrimeBiome if the documented profile fits you: the page positions it for Adults comparing skin-support probiotic gummies. It is a gummies product at $79.00 with 60-day refund window refund terms. If both fit, the refund window and formula disclosure are the tie-breakers, not the marketing.
What would change this verdict
This verdict is not permanent. It would change if a product publishes per-ingredient doses, removes a documented red flag, changes its price or refund window, or adds a product-specific trial. Today, the documented refund gap is 0 days and the score gap is 7.2 points; either can change with the next data refresh. We capture data daily and recompute the score after each refresh; the comparison page follows the data. If you spot a value that no longer matches the official page, report it through the contact page and we will verify it against the source.
What this comparison does not tell you
What this page does not tell you: whether either product is safe for you, whether it will work for your goals, or how it interacts with your medication. For this pair, the documented formula lists 0 named ingredients for Kerafen and 10 for PrimeBiome. The documented price gap is $0.00. Doses are not published for every product in our data; when they are missing, we leave them unknown instead of guessing. Where an ingredient list is missing entirely, we record that as unknown rather than assuming a formula. Reviews are sourced customer statements, not clinical evidence. Use the individual product pages for the full safety and verification notes, and speak to a qualified professional about your own situation. Treat this comparison as a dated snapshot, not a guarantee or a medical recommendation.