These two are closer than most comparison pages admit: on their current labels they share the same ingredients, the same 5% undecylenic acid, the same 15 ml bottle and the same four-times-a-day routine, and they sell at the same price with the same 60-day window. So the tiebreakers are buying terms. Kerassentials counts its 60 days from delivery rather than the order date, accepts empty bottles and ships the 3-bottle package free in the US without conflicting notes, which is why it is our pick in the best nail fungus treatments comparison. MycosynX is the one to choose if you want to be able to call someone: it has a phone line, while Kerassentials support is email only. Neither is a proven cure, and a diagnosis comes first.
Where Kerassentials wins
- The 60-day window starts at delivery, not at the order date
- All bottles accepted back, opened or empty
- Free US shipping on 3 and 6 bottles, stated consistently
Where MycosynX wins
- Phone support (+1 877-257-0825) as well as email
- Its refund also accepts empty bottles
- Keep in mind: its homepage still shows an older spray, and you pay return shipping with either brand
Check Kerassentials price on the official site →Opens the brand's official website · money-back guarantee
Check MycosynX price on the official site →Opens the brand's official website · money-back guarantee
If you have searched for a topical nail product in the last year, these two names have probably both shown up. MycosynX and Kerassentials are marketed for the same thing: the look and condition of the nails and the surrounding skin. Both are oils you apply on the outside of the nail. Neither is something you swallow, and neither should ever be described as a capsule.
This page compares them the way a buyer does: what each one physically is, what each label discloses, what a month costs, how the money-back guarantee works in practice, and who each one fits. Everything about MycosynX comes from its official page and label; Kerassentials details come from its official order page, label image, refund and shipping pages, rechecked in October 2026, as covered in our Kerassentials review.
What each one is, and how you use it
MycosynX, on the direct order page, is sold as a "Fungal Nails Serum", 0.5 oz / 15 ml, label revision 0524. The suggested use on that label is unusually specific: apply four times daily (twice in the morning, twice in the afternoon), using the enclosed brush applicator on the nail plate and a cotton swab to work it into the cuticle, after filing the nail surface with an emery board.
Kerassentials is a 15 ml oil with a brush applicator. Its current label gives the same directions: apply four times a day, twice in the morning and twice in the afternoon, with the brush on the nail and a cotton swab on the cuticle, after gently filing the nail surface. Older copy on its site described an oil "you can apply every day after you shower"; the label on the order page is the one to follow.
So the routines are the same, and the bottles empty at a similar rate. Both brands sell each bottle as a 30-day supply; neither publishes an exact number of applications per bottle.
Undecylenic acid: the ingredient both are built around
Search volume for both brands overlaps heavily with searches for undecylenic acid, and that is no accident, because it is the ingredient both labels lead with.
Undecylenic acid is an established topical antifungal ingredient in the United States: it is the active in a number of over-the-counter products covered by the FDA's monograph for athlete's foot and ringworm, where those products carry a Drug Facts panel stating a percentage. That is the context for the strength both labels now state.
- MycosynX states a strength on the label: Undecylenic Acid USP 5%.
- Kerassentials states the same strength on its current label: undecylenic acid USP (5%).
One more piece of honesty that most comparison pages skip: neither of these products publishes a Drug Facts panel with the ingredient listed as an active. Both are presented as cosmetic-style oils for the appearance of nails and skin, not as monograph drug products, and we could not verify the regulatory classification of either one. Read them as what they say they are.
The two labels, side by side
| MycosynX | Kerassentials | |
|---|---|---|
| Format | Topical serum, external use only | Topical oil, external use only |
| Bottle size | 0.5 oz / 15 ml (label REV 0524) | 15 ml, with brush applicator |
| Named active | Undecylenic Acid USP 5% | Undecylenic acid USP 5% |
| Carrier oils | Isopropyl palmitate, almond oil, flaxseed oil | Isopropyl palmitate, almond oil, flaxseed oil |
| Essential oils | Tea tree, lemongrass, lavender | Tea tree, lemongrass, lavender |
| Other | Aloe vera leaf extract, DL-alpha tocopherol acetate | Aloe vera leaf extract, vitamin E (DL-alpha tocopherol acetate) |
| How often | 4 times daily, plus filing the nail | 4 times daily, plus filing the nail |
| Applicator | Brush applicator and cotton swab per the label (photos show a pump bottle) | Brush applicator and cotton swab per the label |
| Checkout | BuyGoods | BuyGoods |
| Distributor address | 11870 62nd St N, Largo, FL 33773 | 19655 E 35th Dr #100, Aurora, CO 80011 (label and returns) |
| Guarantee | 60 days from the order date | 60 days from delivery |
On the current labels the two lists are the same, in the same order: isopropyl palmitate, undecylenic acid USP 5%, almond oil, flaxseed oil, tea tree oil, aloe vera, vitamin E, lemongrass oil and lavender oil. Both sites also carry leftovers from older versions: the Kerassentials references page shows a longer formula (with mineral oil, walnut, menthol, camphor, clove and other oils), and the MycosynX homepage still shows an older spray. Go by the label on the order page and on the bottle you receive.
Check Kerassentials price on the official site →Opens the brand's official website · money-back guarantee
Check MycosynX price on the official site →Opens the brand's official website · money-back guarantee
What a month actually costs
When we checked (MycosynX in September, Kerassentials in October 2026), both brands ran the same headline ladder: $79, $69 and $49 per bottle for the 2, 3 and 6-bottle packages, which is $158, $207 and $294 in total. Both charged $9.99 shipping on the smallest package and showed free US shipping on the larger ones. One caveat specific to MycosynX: its order page prints "+ shipping" next to the 3-bottle option while its support page says shipping is free for 3 and 6 bottles. Treat the checkout screen as the final word.
Because both are 15 ml bottles used four times a day and sold as 30-day supplies, the cost per month is effectively the same: $49 to $79, depending on the package. The small differences are in the extras: Kerassentials ships 3 bottles free in the US with no conflicting note, and its 6-bottle package adds three e-books (Skin SOS, Barefoot Ready and The Fungal Full Detox Plan).
2 bottles60-day supply$79 /bottle$158 · + shippingCheck availability →Best value
6 bottles180-day supply$49 /bottle$294 · free shipping + bonusesCheck availability →
3 bottles90-day supply$69 /bottle$207 · + shippingCheck availability →The 60-day guarantee, and how each refund really works
Both brands advertise 60 days. The mechanics are where they differ, and the mechanics are what you will deal with if you change your mind.
MycosynX: the order page says to send back any remaining bottles, "even empty ones", and the support page says to return all bottles, empty, full or partially full, within 60 days of the order date. Return shipping is paid by you. Refunds are described as 5 to 10 business days after the return is processed, although the terms page says 3 to 5. Returns go to MycosynX, 11870 62nd St N, Largo, FL 33773, and support is reachable by email and at +1 (877) 257-0825.
Kerassentials: 60 days from the day your package is delivered. Email contact@kerassentials-product.com with "Refund Request" in the subject line, then send all the bottles back, opened or empty, with a note showing your name, email and order number, to 19655 E 35th Dr #100, Aurora, CO 80011, USA. Return shipping is paid by you. The refund page says refunds are processed within a few days of the package arriving and take 5 to 10 days to show on your card. Support is by email only; we found no customer service phone number. Payment runs through BuyGoods.
Both, in other words, are return-the-bottles policies rather than keep-the-bottle policies, and in both cases you pay to ship them back. Neither is a walk-away refund.
Every order from the official MycosynX store is covered by a 60-day money-back guarantee, and it is a one-time payment with no subscription.
What the research on these ingredients actually shows
This is the section where fairness matters most, so let us be exact. Neither MycosynX nor Kerassentials has a published clinical trial of its finished formula that we could find. Research exists on individual ingredients, and it describes those ingredients, not either product.
- Undecylenic acid is a long-established topical antifungal ingredient. An important practical limitation applies to every topical for the nail: the nail plate is a poor surface for anything to pass through, which is why an ex vivo 2024 comparison of prescription and over-the-counter nail antifungals is worth reading before you form expectations of any brushed-on product.
- Tea tree oil, per NCCIH, has a small amount of evidence for athlete's foot and may be weaker than standard treatment; for nail fungus specifically, NCCIH says the amount and quality of research are insufficient.
- Lavender oil has no good evidence for nails, and topical use can irritate skin.
Because the two ingredient lists overlap so heavily, this research applies equally to both. It is not a reason to pick one over the other, and it is not evidence that either one does anything to a nail.
Safety: what applies to both bottles
Both are external-use products. Keep either away from the eyes and mouth, and stop if the skin becomes irritated. Two specific points from the labels are worth repeating because they apply to both: each contains almond oil, which is a consideration if you have a tree-nut allergy (and the older Kerassentials formula also listed walnut oil), and essential oils such as tea tree, lemongrass and lavender are recognised causes of contact dermatitis. Allergic contact dermatitis has also been reported from an undecylenic acid nail solution.
When a nail problem needs a doctor, not a bottle
This is the part no comparison table covers, and it outranks every price difference on this page. A thick, yellow or crumbling nail is not always fungus, and the look alone does not settle it. See a doctor or podiatrist rather than reaching for any bottle if:
- The nail or toe is painful, swollen, red or leaking fluid.
- The problem is spreading to other nails or the surrounding skin.
- You have diabetes, poor circulation, neuropathy or a weakened immune system. NIDDK is explicit that foot and nail problems in diabetes need professional care, because small issues escalate quietly.
- There is a dark brown or black streak running under the nail, or pigment spreading onto the skin around it. That needs an in-person assessment, because melanoma can present this way.
- Nothing has changed after a long, consistent routine.
The American Academy of Dermatology notes that a proper diagnosis usually involves testing a nail sample, because psoriasis, old trauma and other conditions imitate fungus closely.
Who each one fits
MycosynX may fit you if…
- You want a phone line as well as email support.
- You are happy to count your 60 days from the order date.
- You will realistically keep to a four-times-a-day routine, with filing.
Kerassentials may fit you if…
- You want the most time to decide: the 60 days start at delivery.
- You are fine with email-only support.
- You will realistically keep to a four-times-a-day routine, with filing.
If neither point decides it for you, Kerassentials is the one we would start with; see how both rank in our best nail fungus treatments comparison. Either way, the formulas are the same, so there is no reason to buy both.
Check Kerassentials price on the official site →Opens the brand's official website · money-back guarantee
Check MycosynX price on the official site →Opens the brand's official website · money-back guarantee
How to be sure you are on the official MycosynX store
Searches for either brand return a lot of lookalike pages, and for MycosynX they also return Mycosyn Pro, a different and older capsule product with several "official" domains of its own. Before you pay, check three things: the order page is on mycosynx.com, the checkout is a BuyGoods page, and the label image matches the serum described here, with Undecylenic Acid USP 5% and the Largo, Florida address. One thing to expect on the official site itself: it still shows an older 1 oz spray with a different ingredient list, and some copy that calls the product a capsule. That is legacy content, not a second product you are being sold.
For the full label, the price table and our take on the marketing claims, see our MycosynX review and the checks in is MycosynX legit.
Frequently asked questions
Are MycosynX and Kerassentials the same product?
They are separate brands with different support and returns addresses, but their current labels list the same ingredients: undecylenic acid USP 5% with tea tree, lemongrass, lavender, almond and flaxseed oils, aloe and vitamin E in an isopropyl palmitate base. Both sell through BuyGoods.
Which one tells you how much undecylenic acid it contains?
Both do. Each current label states undecylenic acid USP at 5%.
How long does a bottle of each last?
Both are 15 ml bottles applied four times a day and sold as 30-day supplies. Neither brand publishes an exact number of applications per bottle.
Do both have a 60-day money-back guarantee?
Yes, both advertise 60 days, but Kerassentials counts from delivery and MycosynX from the order date. Both ask for all bottles back, including empty ones, and in both cases you pay return shipping. MycosynX returns go to Largo, Florida; Kerassentials returns go to Aurora, Colorado.
Is either one a substitute for seeing a doctor about a nail?
No. Thick or discolored nails can come from psoriasis, injury or, rarely, melanoma, and diagnosis usually needs a nail sample. See a doctor if the nail hurts, the problem is spreading, you have diabetes or poor circulation, or there is a dark streak under the nail.
Is there a study showing either formula works?
Neither brand has a published clinical trial of its finished formula that we could find. The research that exists looks at individual ingredients such as undecylenic acid and tea tree oil, not at these products.
Related reading
Best ofBest nail fungus treatments (2026)
Kerassentials vs MycosynX: same 5% undecylenic acid formula, same price. We compare refund terms, support, website red flags and what a nail oil can really do.
Read more →
ReviewKerassentials review
What the Kerassentials label says is in the nail oil, which ingredients have real evidence, how to use it, what it costs and how the 60-day refund works.
Read more →
ReviewMycosynX review
MycosynX is not something you swallow. It is a 0.5 oz serum you brush onto the nails and cuticles. Here is what the label lists, how it is meant to be used, what it costs and how the refund works.
Read more →
Buy it from the official store so the guarantee applies, and keep your order email until you decide.
Check MycosynX price on the official site →Opens the brand's official website · money-back guaranteeSources
- MycosynX official website, direct order page and product label REV 0524 (mycosynx.com), accessed September 2026
- MycosynX support pages: shipping, returns and refund timing, accessed September 2026
- Kerassentials official order page, label image, references page, refund and shipping pages (thekerassentials.com), accessed October 2026
- Ex vivo comparison of prescription and over-the-counter topical nail antifungals (2024). pubmed.ncbi.nlm.nih.gov/39133361
- Allergic contact dermatitis reported from an undecylenic acid nail solution. pubmed.ncbi.nlm.nih.gov/30537336
- NCCIH: Tea Tree Oil. nccih.nih.gov/health/tea-tree-oil
- NCCIH: Lavender. nccih.nih.gov/health/lavender
- American Academy of Dermatology: nail fungus diagnosis and treatment. aad.org
- NIDDK: Preventing diabetes-related foot problems. niddk.nih.gov
MycosynX