FDA OTC Monograph — Miscellaneous External Drug Products (Wart Removers, Lice Treatments, Dandruff)

Drugstore shelves carry hundreds of topical products for warts, lice, dandruff, corns, and ingrown toenails — products that look like consumer goods but are regulated as drugs under the Federal Food, Drug, and Cosmetic Act (FD&C Act). Their legitimacy rests on FDA's over-the-counter (OTC) drug monograph system: a set of product-class regulations, each specifying the active ingredients, concentrations, dosage forms, and labeling language that make a topical drug product Generally Recognized as Safe and Effective (GRASE). A manufacturer who follows the applicable monograph may market the product without a separate FDA premarket approval. 21 CFR Part 358 consolidates the OTC monographs for five categories of external drug products: wart removers, ingrown toenail relief, corn and callus removers, pediculicides, and dandruff/seborrheic dermatitis/psoriasis products.

Legal Authority

• 21 U.S.C. § 355 — FDCA § 505: OTC monographs provide the regulatory pathway for GRASE external drug products; compliance with 21 CFR Part 358 eliminates the need for an individual NDA
• 21 U.S.C. § 321 — FDCA definitions: external drug products (wart removers, pediculicides, dandruff shampoos) are drugs under FDCA
• 21 CFR Part 358 — FDA OTC monograph for miscellaneous external drug products; specifies GRASE active ingredients, concentrations, dosage forms, labeling requirements, and indications for five product categories

Key Mechanics

Part 358 covers five distinct OTC product categories, each with its own GRASE ingredient list and labeling requirements: wart removers (salicylic acid in specified concentrations and vehicles), ingrown toenail relief (sodium sulfide for softening), corn and callus removers (salicylic acid), pediculicides (pyrethrin, piperonyl butoxide), and dandruff/seborrheic dermatitis/psoriasis products (zinc pyrithione, coal tar, selenium sulfide, salicylic acid). Manufacturers must use only the listed ingredients at approved concentrations, include the required Drug Facts label language, and comply with OTC drug GMP (21 CFR Parts 210-211). Products adding new ingredients or claims outside the monograph require an NDA or de novo administrative order under the OTC Monograph Reform Act of 2020.

Current Rule (2026)

What This Rule Does

The OTC monograph system classifies drug products for self-medication. When the FDA issues an OTC monograph for a category of products, manufacturers can market any product meeting the monograph conditions without filing an individual New Drug Application (NDA). Part 358 governs a cluster of topical drug products that address common self-treatable dermatological conditions — the rule specifies exactly which active ingredients are permitted, at what concentrations, in which dosage forms, with which labeling statements, for each product category.

The CARES Act of 2020 modernized the legal framework: OTC monographs are now issued as administrative orders rather than regulations, and established monograph conditions have the status of final orders that FDA may update through a streamlined process. For Part 358, the monograph conditions that existed before 2020 remain valid under the new statutory framework — manufacturers who have been complying with Part 358 continue to comply with the applicable final orders.

Products not meeting Part 358 conditions (for example, a wart remover with a non-listed active ingredient, or a dandruff product at an unlisted concentration) require an approved NDA or NDA supplement before being marketed — they cannot claim GRASE status under the monograph.

Key Provisions

Subpart B — Wart Remover Drug Products (§§ 358.101–358.150)

• § 358.110 — Permitted active ingredients: OTC wart removers must use one of the following:
  • Salicylic acid 12 to 40 percent in a plaster vehicle (the medicated adhesive patch format, used for plantar warts and larger lesions)
  • Salicylic acid 5 to 17 percent in a collodion-like vehicle (a liquid that dries to a flexible film, common in small bottles with applicator brushes — the classic Compound W format)
  • Salicylic acid 15 percent in a collodion-like vehicle with karaya gum (a medicated bandage variant) Salicylic acid works by keratolysis — breaking down the keratin that makes up the wart's thick outer skin, causing it to soften and eventually peel off; the treatment typically requires weeks of daily application
• § 358.150 — Labeling: the product must identify as a "wart remover"; indications must state one of the approved phrases (e.g., "removes common and plantar warts"); warnings must include: not for use on genital warts, not for diabetics without doctor approval, do not use if wart has hair growing from it, not for use on face, not for children under 12 without doctor supervision; directions must specify how to use, how often to apply, and the maximum treatment period

Subpart D — Ingrown Toenail Relief Drug Products (§§ 358.301–358.350)

• § 358.310 — Permitted active ingredient: the only FDA-approved OTC active ingredient for ingrown toenail relief is sodium sulfide 1 percent in a gel vehicle; sodium sulfide softens the nail, reducing the pressure on the nail bed and relieving pain; the gel is applied to the nail and surrounding tissue; the treatment relieves discomfort but does not correct the underlying nail growth pattern
• § 358.350 — Labeling: product must identify as "ingrown toenail relief product" or "ingrown toenail discomfort reliever"; indications must state one of the approved phrases about relieving pain or discomfort; warnings must note that if condition worsens or doesn't improve, doctor should be consulted; the product may not claim to permanently correct ingrown toenails

Subpart F — Corn and Callus Remover Drug Products (§§ 358.501–358.550)

• § 358.510 — Permitted active ingredients: corn and callus removers use salicylic acid by the same keratolytic mechanism as wart removers, but at concentrations appropriate for the harder tissue of corns and calluses:
  • Salicylic acid 12 to 40 percent in a plaster vehicle
  • Salicylic acid 12 to 17.6 percent in a collodion-like vehicle The upper concentration limits are the same as wart removers (40% plaster), while the liquid form is capped slightly higher for corn/callus (17.6%) than for wart use (17%) — reflecting the typically thicker tissue of corns vs. common warts

Subpart G — Pediculicide Drug Products (§§ 358.601–358.650)

• § 358.610 — Permitted active ingredients: OTC pediculicides (lice treatments) must use the combination of:
  • Pyrethrum extract providing pyrethrins 0.17 to 0.33 percent AND
  • Piperonyl butoxide 2 to 4 percent, in a non-aerosol dosage form Pyrethrins are natural insecticides derived from chrysanthemum flowers that paralyze lice by blocking sodium channels in their nervous systems; piperonyl butoxide is a synergist that inhibits the lice's detoxification enzymes, making the pyrethrins far more effective; the combination has been the standard OTC head lice treatment for decades; the non-aerosol requirement eliminates aerosol sprays, which pose inhalation risks when applied to the head and scalp
• § 358.650 — Labeling: the product must identify as a "lice treatment"; indications must state "treats head, pubic (crab), and body lice"; warnings include: do not use near eyes, do not use on eyebrows or eyelashes, keep out of reach of children, may cause breathing difficulty in people with asthma; directions must specify how to apply, the contact time (typically 10 minutes), and the need for a second treatment 7-10 days later to kill newly hatched lice that were not killed as eggs

Subpart H — Dandruff, Seborrheic Dermatitis, and Psoriasis Drug Products (§§ 358.701–358.760)

• § 358.710 — Permitted active ingredients: the widest ingredient list in Part 358 — the FDA recognizes multiple distinct mechanisms for controlling dandruff, seborrheic dermatitis, and scalp psoriasis:
  • For dandruff control:
    • Coal tar 0.5 to 5 percent (or equivalent coal tar solution concentrations) — the oldest effective dandruff treatment; coal tar slows skin cell turnover and has anti-inflammatory properties; the distinctive smell of coal tar shampoos (Head & Shoulders Coal Tar) is recognizable; higher concentrations are more effective but carry a slight theoretical carcinogenicity concern from polycyclic aromatic hydrocarbons (FDA has reviewed this and maintained the ingredient's GRASE status for OTC dandruff use)
    • Pyrithione zinc (zinc pyrithione) 0.3 to 2 percent — the active in most mainstream dandruff shampoos; zinc pyrithione is antifungal, targeting the Malassezia yeast that contributes to dandruff
    • Salicylic acid 1.8 to 3 percent — promotes skin cell shedding, reducing the visible flaking
    • Selenium sulfide 1 percent — antifungal and anti-seborrheic; Selsun Blue 1% selenium sulfide shampoo is the classic OTC product; higher concentrations (2.5%) require a prescription
    • Sulfur 2 to 5 percent — keratolytic and antifungal; often combined with salicylic acid
  • For seborrheic dermatitis: coal tar 0.5–5%, pyrithione zinc 0.95–2%, salicylic acid 1.8–3%, selenium sulfide 1%, sulfur 2–5% (same ingredient list, reflecting that dandruff and seborrheic dermatitis are on a spectrum)
  • For psoriasis: coal tar 0.5–5% (the only OTC-approved active ingredient for scalp psoriasis; topical corticosteroids for psoriasis require a prescription)
• § 358.720 — Permitted combinations: salicylic acid may be combined with sulfur for dandruff products, provided each ingredient is within its individual concentration range; combinations other than salicylic acid + sulfur are not permitted in OTC dandruff products without a separate NDA

How It Affects You

If you manufacture OTC external drug products: your product must comply with the applicable Part 358 subpart — the right active ingredient, the right concentration, the right dosage form, and the required labeling language, verbatim. Deviating from these specifications (using a different concentration, adding a non-listed active ingredient, omitting a required warning) means the product is not covered by the monograph and requires an approved NDA or NDA supplement before marketing. Under the CARES Act OTC reform, FDA can now update monograph conditions through an administrative order process faster than notice-and-comment rulemaking — check the FDA's OTC Monograph Order webpage for the current status of each product category. Products marketed as OTC drugs must also comply with FDA labeling regulations (21 CFR Part 201) including Drug Facts labeling format.

If you are a consumer: the active ingredients and concentrations on OTC product Drug Facts labels tell you exactly what's in the product. For wart removers, salicylic acid concentration determines how aggressive the treatment is — lower concentrations (5%) for small soft warts, higher concentrations (40% plaster) for thicker plantar warts. For dandruff shampoos, the active ingredient tells you the treatment mechanism: zinc pyrithione (antifungal), coal tar (anti-proliferative), selenium sulfide (antifungal), or salicylic acid (keratolytic); some patients respond better to one mechanism than another. For lice treatments, the pyrethrins/piperonyl butoxide combination requires a second treatment 7-10 days after the first — a step many users skip, causing treatment failure as newly hatched nymphs survive. Resistance of Pediculus humanus capitis (head lice) to pyrethrin-based OTC treatments has increased in recent decades; prescription alternatives (spinosad, topical ivermectin, malathion) are available when OTC products fail.

If you are a pharmacist or healthcare provider: Part 358 products are legally available without a prescription but may benefit from professional guidance on product selection and proper use. Recommend the second lice treatment application consistently — resistance is best minimized by thorough application and proper timing. For persistent dandruff or seborrheic dermatitis, combination approaches (alternating zinc pyrithione and coal tar or selenium sulfide) may be more effective than a single product. Patients with scalp psoriasis should be aware that OTC coal tar products are the only Part 358-approved option — prescription topical corticosteroids, calcipotriene, or biologics offer superior efficacy for moderate-to-severe scalp psoriasis.

Statutory Authority

This rule implements:

• 21 U.S.C. § 355 — New drug approval requirements (OTC monograph products are exempt from individual NDA review when meeting monograph conditions)
• 21 U.S.C. § 321(p) — Definition of "new drug" and the GRASE standard
• 21 U.S.C. § 352 — Misbranding provisions (products not meeting monograph labeling requirements are misbranded)
• 21 U.S.C. §§ 360fff–360fff-8 — OTC Drug Monograph Reform (CARES Act of 2020, Title III): converted OTC monograph conditions from regulations into administrative orders; authorized expedited FDA order process for adding, removing, or modifying monograph conditions

Recent Rulemakings

• CARES Act of 2020 (Pub. L. 116-136, Title III) — OTC Drug Monograph Reform: enacted administrative order mechanism to replace notice-and-comment rulemaking for OTC monograph updates; existing Part 358 conditions deemed final orders under the new framework; FDA issued implementing guidance in 2022 on the administrative order process
• 85 FR 30662 (May 2020) — FDA finalized the OTC Drug Facts labeling format requirements (21 CFR Part 201) applying to all OTC drugs including Part 358 products; required standardized formatting, font sizes, and layout for consumer-facing Drug Facts boxes

Pending Action