Our verdict on Kerassentials
What we liked
- A topical oil, so there is nothing to swallow
- Full ingredient list printed on the label, with undecylenic acid at a stated 5%
- 60-day refund window from delivery, through BuyGoods
- One-time payment with no subscription, and free US shipping on 3 and 6 bottles
Watch out for
- No published trial of Kerassentials itself
- Only one ingredient amount (undecylenic acid 5%) is printed
- Two different labels on the vendor's own site (9 vs 17 ingredients)
- Four applications a day, every day, for months
- Contains almond and possibly walnut oil, plus essential oils that can irritate skin
- Refunds mean mailing every bottle back at your own cost, and BBB lists the seller with an F rating
TonicNest may earn a commission if you buy through links on this page, at no extra cost to you. That does not change what we report.
Kerassentials is a brush-on nail oil sold online for toenail and fingernail concerns, and the short answer on whether it is worth buying is that nobody has published a test of the finished product. The label lists one amount, undecylenic acid at 5%[5], while studies of that acid on skin used roughly 10% to 25%[10]. Every other oil in the bottle is listed without a dose.
What is Kerassentials and what does the vendor claim?
The sales video headline calls it a "3-Minute Shower Hack," and the vendor's FAQ says the undecylenic acid "will make the fungus self-destruct"[2]. Those are vendor claims with no product data behind them. The vendor also says its tests show results in "around 9-12 weeks," but those tests are not published[2].
The product is sold through BuyGoods, which the site footer names as "the retailer"[8]. The distributor listed on the bottle is Kerassentials, 19655 E 35th Dr #100, Aurora, CO 80011. The vendor counts one bottle as a 30-day supply.
Kerassentials facts at a glance
Kerassentials is a topical oil, not a capsule, with a 60-day refund window and prices from $158 to $294 per order. The table pulls each fact from the vendor's own pages and label images.
| Item | What we found |
|---|---|
| What it is | Nail and cuticle oil with undecylenic acid and plant oils[5] |
| Form | 0.5 oz / 15 ml bottle, brush applicator, external use only[5] |
| Directions | Apply 4 times daily, twice in the morning and twice in the afternoon[2] |
| Amounts disclosed | Only undecylenic acid USP 5%; all other items unquantified[5][6] |
| Price range | $158 (2 bottles) to $294 (6 bottles), checked October 19, 2026[7] |
| Refund window | 60 days from delivery, all bottles mailed back at your cost[3] |
| Retailer | BuyGoods, Wilmington, DE[8] |
| Shipping | Free in the US on 3 and 6 bottles, 5-7 working days[4] |
| Where it is not sold | The vendor lists no Amazon or Walmart store; its site is the only seller it names[1] |
Who might consider Kerassentials, and who should not?
Kerassentials may interest adults who want a cosmetic nail oil, accept the cost and the four-times-a-day routine, and have already had a doctor look at the nail. It is a poor fit for anyone with a nut allergy, sensitive skin, diabetes, or a nail problem that has never been checked.
Thick, discolored or crumbly nails have several causes, and a fungal infection is only one of them. A doctor or podiatrist can take a nail sample and confirm what is going on before you spend $158 or more.
Skip it, or ask first, if any of these apply:
- You are allergic to tree nuts: both labels list almond oil, and the 17-item label adds walnut oil[6]
- You have reacted to tea tree, lavender or other essential oils
- You have diabetes, poor circulation or a weak immune system
- You are pregnant or breastfeeding
- The oil would be within reach of children, since camphor is toxic if swallowed[16]
How does Kerassentials claim to work?
The vendor claims the oils soak into the nail and the undecylenic acid "will make the fungus self-destruct," and that it prevents new fungus "anywhere on your body"[2]. No data on Kerassentials supports those claims, and they come only from the seller.
What is known is narrower. Undecylenic acid is an antifungal that beat placebo for athlete's foot in powder form[10]. Nails are harder to reach than skin: a lab study found that 25% over-the-counter undecylenic acid solutions got through nail tissue far less well than the prescription drug efinaconazole[11]. Kerassentials uses 5%.
The vendor's reference page links to papers on nail fungus, clove, lavender, flax and tea tree, and none of them tested Kerassentials[19]. The full breakdown is in our guide on whether Kerassentials works on toenail fungus.
What ingredients are in Kerassentials?
Kerassentials lists either 9 or 17 ingredients, depending on which label image you look at on the vendor's site. Only undecylenic acid has an amount (5%). Check the label on the bottle you receive, because the two versions differ.
Label A, on a clear glass bottle, lists 9 items[5]. Label B, on an amber bottle, lists 17 and adds mineral oil, canola, walnut, menthol, camphor, clove, jojoba, chia and manuka oil[6]. The sales page says "No Chemicals," yet the labels list mineral oil, isopropyl palmitate, menthol and camphor[1].
| Ingredient | Label | Dose disclosed | Human evidence for nails or skin | Grade |
|---|---|---|---|---|
| Undecylenic acid USP | A, B | Yes, 5% | Beat placebo for athlete's foot at higher strengths[10]; no nail trial, one small uncontrolled pilot[21] | Moderate (skin), Weak (nails) |
| Tea tree oil | A, B | No | 100% oil on nails, 117 people, 6 months, no placebo group[12] | Limited |
| Lavender oil | A, B | No | Lab studies only[22] | Weak |
| Lemongrass oil | A, B | No | Lab studies only[23] | Weak |
| Clove bud oil | B | No | Lab activity against dermatophytes and Candida[17] | Weak |
| Manuka oil | B | No | 2% cream did no better than the base cream for eczema[18] | Weak |
| Camphor and menthol | B | No | Only a Vicks VapoRub case series of 18 people[15] | Weak; Avoid swallowing |
| Almond, walnut, flax, chia, canola, jojoba oils | A, B (walnut, chia, canola, jojoba on B only) | No | Carrier oils; not studied for nails | Not graded |
| Aloe vera, vitamin E, mineral oil, isopropyl palmitate | A, B (mineral oil B, isopropyl palmitate A) | No | Base ingredients; not studied for nails | Not graded |
Each item is covered in more depth on our Kerassentials ingredients list page.
Does Kerassentials work for nail fungus?
No one knows whether Kerassentials works for nail fungus, because the finished product has never been tested in a published trial. Some of its ingredients have small or lab-only studies, mostly at strengths higher than, or unknown relative to, what is in this bottle.
Here is the evidence, from strongest to weakest:
- Finished product: no published trial. The vendor's "9-12 weeks" figure comes from tests it has not shared[2].
- Undecylenic acid on skin: a 1980 powder trial for athlete's foot beat placebo with no adverse reactions reported[10]. Skin is not nail, and those products held more acid than 5%.
- Undecylenic acid on nails: one uncontrolled pilot that combined it with other agents[21], and a lab study showing weak nail penetration even at 25%[11].
- Tea tree oil on nails: in a 6-month study of 117 people, 100% tea tree oil cleared fungus on lab culture in 18% of users, against 11% for 1% clotrimazole, with no placebo group[12]. The share of tea tree oil in Kerassentials is not stated.
- Other oils: lab dishes only, or no data at all.
Nails grow slowly, so any change takes months to show. The vendor's own refund page advises using the product "at least 3 months," which runs past its 60-day refund window[3].
Kerassentials side effects: who should ask a doctor first?
The main Kerassentials side effects to expect are skin irritation and allergic reactions from the essential oils and nut oils, plus poisoning risk if the oil is swallowed. The label says to stop if irritation occurs, avoid the eyes and keep it from children[5].
- Tea tree oil: 3.8% of people in an athlete's foot trial had moderate to severe dermatitis[13], and allergic reactions have been reported from toenail use[14].
- Camphor: 500 mg has been cited as fatal in children, with seizures at 750 to 1,000 mg[16]. Store the bottle out of reach.
- Almond and walnut oil: tree-nut sources, so a caution for anyone with a nut allergy[6].
- Menthol, lavender, lemongrass, clove: can irritate or sensitize skin.
The pack of sources we used lists no drug interactions for this oil. If you are pregnant, breastfeeding, have diabetes or use other skin products on the same area, ask a doctor or pharmacist first.
See a doctor right away if:
- Redness, swelling or warmth spreads from the nail into the toe or foot
- There is pus, a bad smell, or you have a fever
- The skin blisters, cracks open or bleeds after applying the oil
- You have diabetes and notice any new foot sore or color change
- Someone, especially a child, swallows the oil
More detail is on our Kerassentials side effects page.
What do Kerassentials complaints and buyer reports show?
The clearest public signal is the Better Business Bureau: a search on October 19, 2026 returned one listing, "Kerassentials Company," not accredited and rated F[9]. The BBB profile page itself was blocked, so the number and content of complaints were NOT checked.
Trustpilot returned an error and an archived copy could not be loaded, so Trustpilot ratings were NOT checked. On the FDA side, openFDA returned no recall records and no adverse event reports (CAERS) under the Kerassentials name[20]. FDA warning letters were NOT checked.
The vendor's "over 95,000 Customers" and "14,576 reviews" figures have no source we could verify[1], and its Month 1, 3 and 6 nail photos are unattributed. Read more in Kerassentials complaints and buyer reports.
How much does Kerassentials cost?
Kerassentials costs $158 for 2 bottles plus $9.99 shipping, $207 for 3 bottles, or $294 for 6 bottles, checked October 19, 2026[7]. The 6-bottle order works out to $1.63 a day, against $2.80 a day on 2 bottles with shipping.
2 bottles
6 bottles
3 bottles| Package | Per bottle | Total | US shipping | Cost per day |
|---|---|---|---|---|
| 2 bottles | $79 | $158 | $9.99 | $2.80 |
| 3 bottles (2+1) | $69 | $207 | Free | $2.30 |
| 6 bottles (3+3) | $49 | $294 | Free | $1.63 |
All prices checked October 19, 2026. Checkout totals load by script and tax was not confirmed. After checkout the vendor offers 3 more bottles for $87, 6 more for $174, or a 2-bottle downsell for $58[7]. Decline any add-on you did not plan for. The "was" prices of $358 to $1,074 are the vendor's own reference figures.
Current deals and coupon checks are on our Kerassentials price and coupon page.
What is the Kerassentials refund policy?
Kerassentials has a 60-day refund window that starts on the day your order is delivered, handled through the vendor's support team with BuyGoods as retailer[3].
- Email support with "Refund Request" in the subject line.
- Mail back all bottles, empty or not, with a note (name, email, order ID) and the packing slip to 19655 E 35th Dr #100, Aurora, CO 80011.
- Wait 5 to 10 days for processing.
Return shipping is not refunded. The sales page says "just write to us and we'll refund every single cent"[1], which does not match the mail-back rule on the refund page. It is a one-time payment with no recurring shipments[2].
Where can you buy Kerassentials?
The vendor sells Kerassentials only through its own site, with BuyGoods processing the order[8]. It names no Amazon or Walmart store.
A bottle bought from a third-party listing may not come with the 60-day refund, and you cannot confirm how it was stored or which of the two labels it carries. If you see the oil on a marketplace, check who the seller is before paying. US orders of 3 or 6 bottles ship free in 5-7 working days; Canada, the UK, Ireland, Australia and New Zealand pay $15.95 and wait 10-15 working days[4]. See Kerassentials on Amazon and Walmart for what we found.
Is Kerassentials legit?
Kerassentials is a real product sold through a real retailer, BuyGoods, with a published refund address in Aurora, Colorado[3]. Several facts call for caution, though.
- The vendor domain was registered on January 12, 2022.
- The terms page names no operating company or address[8].
- BBB lists the seller as not accredited with an F rating[9].
- The "FDA registered facility" badge names no facility, and registration is not FDA sign-off on the product[2].
We weigh each of these on is Kerassentials legit, and the complaints page covers buyer reports.
Kerassentials vs other approaches to nail fungus
Kerassentials has less direct evidence than higher-strength antifungal products and a lab-confirmed diagnosis from a doctor. The table compares what each option offers, based on the studies in our sources.
| Approach | Strength | Limitation |
|---|---|---|
| Kerassentials oil | Contains 5% undecylenic acid and tea tree oil | No product trial; most doses unstated[5] |
| Over-the-counter undecylenic acid (10% to 25%) | Beat placebo for athlete's foot[10] | Poor nail penetration in lab tests[11] |
| Pure tea tree oil | 18% culture clearance in one 6-month nail study[12] | No placebo group; allergy risk[14] |
| Camphor and menthol rub | Cheap and widely sold | 18-person case series, no control group[15] |
| Doctor or podiatrist visit | Nail sample confirms the cause; prescription options such as efinaconazole[11] | Costs a visit; some drugs need monitoring |
Our standards for comparing products are on the TonicNest how we check products page.
How do you take Kerassentials?
Kerassentials is not taken by mouth. The label and FAQ say to "Apply 4 times daily (twice in the morning and twice in the afternoon)"[2]: shake the bottle, file the nail surface with an emery board, brush the oil onto the nail, and use a cotton swab to work it into the cuticle. Do not swallow it, and keep it away from your eyes[5]. Step-by-step notes are on how to use Kerassentials.
Kerassentials: final take
Kerassentials may suit an adult with no nut or essential-oil allergy who has had the nail checked by a doctor, wants a plant-oil product, and can keep up four applications a day for several months. The label is clear on directions and cautions, and the 5% undecylenic acid is a known antifungal ingredient.
Skip it if you want a product with its own published trial, if you have diabetes or circulation problems, or if mailing every bottle back at your cost would stop you from using the refund. Plan the timeline too: the vendor quotes 9 to 12 weeks, and the refund window closes at 60 days after delivery.
Frequently asked questions
What is Kerassentials used for?
The vendor sells Kerassentials as a brush-on oil for toenails and fingernails affected by fungus. It is a cosmetic topical oil with 5% undecylenic acid and plant oils. No published trial has tested the finished product, so any benefit is unproven.
Is Kerassentials effective for toenail fungus?
There is no published study of Kerassentials itself. Undecylenic acid helped athlete's foot at 10% to 25% on skin, and 100% tea tree oil was tested on nails, but this oil lists only 5% acid and no tea tree amount.
What are the Kerassentials directions for use?
The label says to apply it 4 times daily, twice in the morning and twice in the afternoon. File the nail with an emery board, shake the bottle, brush oil on the nail and use a cotton swab on the cuticle.
How long does Kerassentials take to show results?
The vendor says around 9 to 12 weeks, based on tests it has not published. Another vendor page mentions improvements in the first weeks. Nails grow slowly, and the refund window closes 60 days after delivery.
Can I buy Kerassentials at Walmart or on Amazon?
The vendor names no Walmart or Amazon store and sells through its own site, with BuyGoods as retailer. A marketplace bottle may not carry the 60-day refund, and you cannot confirm which label version or storage it had.
Is there a Kerassentials coupon or discount?
We found no coupon code. The lower per-bottle price comes from package size: $49 a bottle on 6 bottles, $69 on 3 and $79 on 2, checked October 19, 2026. Post-checkout add-ons are optional and can be declined.
Is Kerassentials safe for people with nut allergies?
Not without asking a doctor first. Both labels list sweet almond oil, and the 17-ingredient label adds walnut oil. It also contains essential oils, such as tea tree and lavender, that can cause allergic skin reactions.
What does the FDA registered facility badge on Kerassentials mean?
The vendor shows a badge saying the oil is made in an FDA registered facility, but it does not name the facility or the certifier. Registering a facility with the FDA is not an FDA sign-off on the product itself.
Does Kerassentials have a subscription?
No. The vendor FAQ says it is a one-time payment with no recurring shipments. After checkout you will see optional add-on offers for more bottles at $29 each, which you can decline.
What happens if someone swallows Kerassentials?
The label says do not ingest and to seek medical help if swallowed. The 17-ingredient label includes camphor, which is toxic by mouth, especially for children. Get medical help right away rather than waiting for symptoms.
Sources
- Kerassentials sales page. Kerassentials vendor site, read October 19, 2026.
- Contact us and FAQ. Kerassentials vendor site, read October 19, 2026.
- Refund policy. Kerassentials vendor site, read October 19, 2026.
- Shipping policy. Kerassentials vendor site, read October 19, 2026.
- Product label A (9 ingredients). Kerassentials vendor site, read October 19, 2026.
- Product label B (17 ingredients). Kerassentials vendor site, read October 19, 2026.
- Package price data. Kerassentials vendor site, read October 19, 2026.
- Terms and conditions. Kerassentials vendor site, read October 19, 2026.
- BBB search: Kerassentials. Better Business Bureau, read October 19, 2026.
- Undecylenic acid powder trial for tinea pedis (1980). PubMed, read October 19, 2026.
- Nail penetration of OTC undecylenic acid vs efinaconazole. PubMed, read October 19, 2026.
- Tea tree oil vs clotrimazole for onychomycosis. PubMed, read October 19, 2026.
- Tea tree oil 25% and 50% for interdigital tinea pedis. PubMed, read October 19, 2026.
- Allergic reaction to tea tree oil used on toenails. PubMed, read October 19, 2026.
- Vicks VapoRub on toenails: case series. PubMed, read October 19, 2026.
- Camphor poisoning in children. PubMed, read October 19, 2026.
- Clove oil activity against dermatophytes and Candida. PubMed, read October 19, 2026.
- Manuka oil 2% cream in eczema: randomized trial. PubMed, read October 19, 2026.
- References. Kerassentials vendor site, read October 19, 2026.
- openFDA CAERS adverse event search: Kerassentials. US Food and Drug Administration, read October 19, 2026.
- Undecylenic acid nail pilot study. PubMed, read October 19, 2026.
- Lavender oil antifungal lab study. PubMed, read October 19, 2026.
- Lemongrass oil antifungal lab study. PubMed, read October 19, 2026.
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