Why Are My Nails Peeling in Layers?
Nails that split into thin layers at the tip have a name: lamellar onychoschizia. Here is why water, solvents and gel removal cause it, and what helps.
Short answer: nails that split into thin horizontal sheets at the tip have lamellar onychoschizia, a type of nail fragility in which the “glue” between the nail’s stacked keratin layers fails. The usual causes are external: hands that are wet and dried many times a day, solvents such as acetone, gel polish that is picked or scraped off, and repeated small knocks to the free edge. Fixing the habit that strips the nail, sealing in moisture with an occlusive product, and filing instead of tearing will help most people; biotin has only small, uncontrolled studies behind it.
How a nail plate is built, and why it splits sideways
A fingernail looks like a single sheet, but it is a laminate. A 2020 review in Dermatology and Therapy by an international group of nail specialists (Chessa and colleagues) describes the normal nail plate as about 25 layers of tightly packed keratinized cells, 0.5 to 1 mm thick. About two thirds of the plate is made by the proximal matrix under the cuticle fold, and the rest by the distal matrix and nail bed.
Two different properties matter here:
- Hardness comes from keratin rich in the sulfur amino acid cystine and from tight keratin cross-links. The review notes that nail keratin is hardest at a slightly acidic pH.
- Cohesion between layers comes from membrane-coating granules and lipids (the review names cholesterol sulfate among them) that bind one cell layer to the next. Normal nails contain about 5% lipids, and cholesterol sulfate in the plate falls with age, especially after menopause.
Lamellar onychoschizia is a cohesion problem. The review defines it as splitting “caused by the impairment of intercellular adhesive factors,” so the free edge exfoliates into fine horizontal layers. That is different from onychorrhexis, where the nail splits lengthwise along ridges, and from superficial keratin granulation, the chalky white patches that appear when polish is worn for months and layered over old coats.
The authors estimate that nail fragility affects up to 20% of people, more often women over 50, and fingernails far more than toenails. That last point is a useful clue: toenails see less water and fewer solvents.
The four main causes
1. Wet-dry cycling
Nail keratin absorbs water and swells, then shrinks as it dries. Each cycle strains the bonds between cell layers. Chessa and colleagues describe repeated wetting and drying as causing “fractures between nail plate onychocytes” and point to household workers, hairdressers and nurses as typical patients. They also flag a less obvious trigger: occlusive gloves pulled on over wet hands, which keep the nail soaked for hours.
The American Academy of Dermatology (AAD) gives the same practical advice in its healthy-nail tips: too much water exposure can weaken nails “causing them to split, peel, or break,” so wear gloves for cleaning and dishes and moisturize after hand washing.
Water content itself is debated. Some studies cited in the review linked brittle nails to water content below 16%, while others found no difference between brittle and normal nails. The repeated swelling and shrinking matters more than the absolute amount of water at any one time.
2. Solvents, including acetone
Acetone and other solvents remove polish by dissolving it, and they also dissolve the lipids between nail cells. The 2020 review states that occupational exposure to solvents “can dissolve intercellular lipids and damage intercellular cohesion.” Frequent full-hand soaks in remover expose the nail and surrounding skin to the most solvent for the longest time.
3. Gel polish removal and long-wear polish
The AAD’s gel manicure guidance says gel manicures “can cause nail brittleness, peeling and cracking.” Its removal advice is specific: soak only your fingertips in acetone rather than whole hands, and do not pick at the polish or pry it off with other nails or tools. Gel adheres tightly to the nail surface; when it is lifted off by force, it can take the top layers of the plate with it, leaving a thinner, rougher nail that splits more easily at the tip.
4. Mechanical trauma
Using nails as tools, tapping on keyboards and phone screens, and repeated knocks during manual work all load the free edge. The review lists mechanical micro-trauma from routine occupational activity, along with nail picking (onychotillomania) and nail biting, as causes of brittleness. The AAD adds that biting nails and removing cuticles can damage the nail.
A note on nail hardeners
Some hardeners contain formaldehyde. The FDA’s nail care products page (content current as of October 15, 2024) explains that formaldehyde bonds with nail keratin to make the nail harder, but “using these nail hardeners often, however, may make nails brittle and more likely to break or peel,” and the ingredient can cause irritation and allergic reactions. A harder nail is also a less flexible one, which is the opposite of what a peeling nail needs.
Cause-to-fix diagnostic table
Match what you see to the likeliest trigger, then start with the matching fix. Most people have two or three of these at once.
| What you notice | Likely trigger | First fix | How you will know it worked |
|---|---|---|---|
| Thin sheets peel from the tip of several fingernails; toenails are fine | Wet-dry cycling from dishes, cleaning, frequent hand washing | Gloves for wet work; occlusive moisturizer on nails after every wash | New nail at the cuticle grows in smooth and stays intact as it reaches the tip over the following months |
| Peeling began after you started gel manicures | Gel removal stripping top layers; acetone soaks | Fingertip-only acetone soaks, no picking or scraping; longer breaks between sets | Fewer splits on the regrown nail after one or two cycles without gel |
| Nails feel dry and chalky after polish changes; white patches | Frequent remover use; polish worn for months and layered | Fewer polish changes; moisturize right after removal; bare-nail periods | Surface looks clearer and less flaky on new growth |
| Splits worse on the dominant hand or the fingers you type with | Mechanical trauma at the free edge | Keep nails shorter, file with a fine emery board in one direction, stop using nails as tools | Fewer new splits within weeks, since shorter edges take less load |
| Nails got harder but now crack and peel | Frequent formaldehyde hardener use | Stop the hardener; use a moisturizer or a flexible film-forming lacquer instead | Fewer cracks once the hardened section grows out |
| Peeling with pitting, thickening, color change, lifting, or toenail involvement | Possible skin or nail disease (for example psoriasis, lichen planus, eczema, fungal infection) | See a board-certified dermatologist | A diagnosis that explains the pattern |
What the research says about fixes
| Claim | Best evidence | Study type, size, duration | Strength |
|---|---|---|---|
| Repeated wetting and drying and solvents cause layered splitting | Chessa et al., Dermatology and Therapy, 2020 | Narrative review by 17 nail specialists of literature to August 2019 | Limited |
| Gloves and moisturizing after washing reduce splitting and peeling | AAD healthy-nail tips | Professional-body guidance | Guidance |
| Oral biotin increased nail thickness and reduced splitting | Colombo et al., J Am Acad Dermatol, 1990 | 32 people: 10 normal-nail controls, 8 brittle-nail patients measured before and after biotin, 14 with less precisely timed clippings; electron microscopy | Limited |
| Biotin led to self-reported improvement | Hochman et al., Cutis, 1993 | Retrospective review, 35 patients, six-month window | Limited |
| Biotin’s nail evidence needs larger controlled trials | Lipner and Scher, J Dermatolog Treat, 2018 | Literature review | Limited |
| Frequent formaldehyde hardener use can make nails peel | FDA nail care products page, 2024 | Regulator guidance | Guidance |
Moisturizers and occlusives
The 2020 review calls nail moisturizers “useful in patients with” brittle nails and describes what to look for: occlusive materials such as petrolatum or lanolin, humectants such as glycerin and propylene glycol, and sometimes alpha-hydroxy acids or urea to increase the plate’s ability to hold water. The point is to slow water loss and buffer the swell-shrink cycle, not to “feed” the nail.
Practical routine: after washing and drying your hands, rub a pea-size amount of petrolatum, a thick ointment or a urea-containing hand cream into each nail plate, the free edge and the cuticle. At night, a heavier layer under cotton gloves gives the longest contact time.
INCI clues on a hand cream or nail balm:
- Occlusives: Petrolatum, Lanolin, Cera Alba (beeswax), Butyrospermum Parkii (shea) butter, Dimethicone
- Humectants: Glycerin, Propylene Glycol, Urea
- Lipids that mirror the nail’s own cement: Ceramide NP, Cholesterol
Strengthening lacquers
The review describes two film-forming approaches. A lacquer based on hydroxypropyl chitosan (HPCH) was studied in people with fingernail onychoschizia and is thought to work through its affinity for keratin. A lacquer with 16% polyureaurethane forms a flexible, waterproof barrier. In both cases the product is a coat applied once daily; it shields the plate from water and solvents while new nail grows in. Look for these ingredients on the label rather than for “hardening” claims, which often mean formaldehyde or similar cross-linkers.
Biotin: what the studies actually show
Biotin is the most-searched fix for peeling nails, and the evidence is thinner than its popularity suggests.
- Colombo et al. (1990) examined fingernail clippings by scanning electron microscopy. In the 8 patients whose clippings were timed before and after biotin, nail thickness rose by 25%; in 14 patients with less precise timing, it rose by 7%. Splitting decreased in both groups and the surface cell pattern became more regular. The comparison group was 10 people with normal nails, not people taking a placebo.
- Hochman et al. (1993) reviewed records from a nail practice over six months. Of 35 patients taking daily biotin, 22 (63%) showed improvement on subjective evaluation and 13 (37%) reported no change.
- Lipner and Scher (2018) reviewed the literature and concluded that larger controlled trials are needed to determine efficacy and dosing.
- Chessa et al. (2020) note that biotin studies “were small, not well controlled,” report that 5-10 mg a day for 3-6 months is the usual recommendation, and warn that intakes above 10 mg a day can cause falsely high or low lab results. Tests for troponin (heart attack), thyroid hormones, prolactin and pregnancy are among the most affected.
A reasonable position: biotin may help some people with idiopathic brittle nails, but it will not undo damage from water and solvents that continue every day. If you take it, mention it before any blood test.
The same review notes that iron supplementation may help when ferritin is very low (below 10 ng/mL) and zinc when there is a deficiency, which is a reason to ask about bloodwork if peeling arrives with fatigue, hair shedding or a restrictive diet, rather than self-supplementing.
When peeling may point to a condition
Chessa and colleagues separate primary “brittle nail syndrome” from fragility that is secondary to something else. Secondary causes include inflammatory skin diseases that involve the nail (psoriasis, lichen planus, eczema, alopecia areata), fungal infection, poor peripheral circulation, nutritional deficiencies, and medicines such as oral retinoids and some chemotherapy drugs. They specifically note that proximal layered splitting, starting near the cuticle rather than at the tip, can occur in lichen planus or during retinoid therapy.
Signals that fit a cause other than everyday wear:
- Splitting that starts at the cuticle end, not the free edge
- Toenails peeling as much as fingernails
- Pitting, ridges with thickening, yellow or white discoloration, or the nail lifting off the bed
- Pain, swelling or redness around the nail
- New peeling alongside medication changes, fatigue or hair shedding
The AAD’s rule of thumb is that nails that change, swell or hurt should be seen. If your pattern matches any of the list above, book a visit with a board-certified dermatologist.
Mistakes that keep nails peeling
- Peeling off the loose layer. It pulls up deeper layers. Trim or file it instead.
- Filing back and forth with a coarse file. Sawing motion frays the layers. Use a fine emery board in one direction, rounding the tip slightly.
- Full-hand acetone soaks. Limit solvent contact to the fingertips, and moisturize immediately after.
- Moisturizing only the skin. Rub the product into the nail plate and free edge, where the layers are separating.
- Back-to-back gel sets. Each removal thins the plate. Give nails time to grow out between sets.
- Relying on a hardener. Frequent formaldehyde hardeners can make nails more brittle.
Gel manicures and lamps
If gel polish is part of your routine, the curing lamp is a separate question from the peeling. We cover the UV exposure studies, including the 2023 cell study that made headlines, in Are UV nail lamps safe?.
Related reading
- Why does my gel manicure lift? for prep and curing mistakes that shorten wear.
Sources and research notes
A 2020 international review of nail fragility (full text), biotin studies on brittle nails from 1990, 1993 and 2018 (PubMed abstracts), AAD healthy-nail and gel manicure guidance, and the FDA nail care products page, checked on the date shown.
Source record date: 2026-10-06. Prices and availability are as of that date.
- Chessa et al. 2020, Pathogenesis, clinical signs and treatment recommendations in brittle nails (Dermatol Ther)
- Colombo et al. 1990, Biotin for brittle fingernails and onychoschizia, scanning electron microscopy (J Am Acad Dermatol)
- Hochman et al. 1993, Brittle nails: response to daily biotin supplementation (Cutis)
- Lipner and Scher 2018, Biotin for the treatment of nail disease: what is the evidence? (J Dermatolog Treat)
- American Academy of Dermatology: 11 dermatologists' tips for healthy nails
- American Academy of Dermatology: Gel manicures, tips for healthy nails
- FDA: Nail care products (content current as of 2024-10-15)
Frequently asked questions
Why do my nails peel in layers at the tip?
The nail plate is built from roughly 25 layers of flattened keratin cells held together by lipids and adhesive proteins. When that cement weakens, the free edge splits horizontally into sheets. The most common triggers are repeated wetting and drying, solvents such as acetone, gel or polish removal by picking, and everyday mechanical trauma.
Does biotin help peeling nails?
The evidence is small. A 1990 scanning electron microscopy study of 8 people with brittle nails measured a 25% increase in nail thickness after biotin, and a 1993 retrospective review found 22 of 35 patients reported improvement. Neither was placebo-controlled. Doses above 10 mg a day can distort some lab tests, so tell your clinician before bloodwork.
Is acetone bad for nails that peel?
Solvents dissolve the lipids that bind nail cells together, which is one mechanism behind layered splitting. If you wear gel polish, the American Academy of Dermatology suggests soaking only the fingertips in acetone and never picking the gel off. Follow removal with a thick moisturizer or petrolatum on the nail and cuticle.
How long until peeling nails grow out?
The peeling tip is old nail, so it does not repair itself; it has to grow out and be trimmed away. Better habits show up first as smoother new growth at the cuticle end. That is why the biotin and nail lacquer studies summarized in a 2020 review were run over three to six months.
When is peeling a sign of something more serious?
Peeling limited to the tips of fingernails and linked to water or polish habits is usually cosmetic. Peeling that starts at the cuticle, affects toenails, comes with pitting, thickening, discoloration, lifting, pain or swelling, or appears alongside fatigue or hair shedding is worth showing to a board-certified dermatologist.