Urea 40% | Salicylic Acid 5%

Applied topically once or twice daily to affected hyperkeratotic areas. Apply a generous layer to clean, dry skin and rub in thoroughly. Suitable for focal areas of hyperkeratosis such as plantar surfaces, heels, elbows, and knees. For nail dystrophy, apply to the nail plate; occlusion may be used if directed by the prescriber to enhance penetration. Avoid contact with healthy surrounding skin (salicylic acid may cause irritation), open wounds, and mucous membranes. Wash hands after application unless the hands are the treatment site.

Apply to affected areas once or twice daily as directed by the prescribing clinician. Due to the salicylate content, application should be limited to focal areas and not used on large surface areas simultaneously. Prescriber will adjust frequency based on response and tolerability.

• For plantar hyperkeratosis or calluses: apply BID; debridement of loosened tissue may be appropriate
• For extensive or large-area disease: prescriber should assess salicylate absorption risk, particularly in children or patients with renal impairment
• Reassess clinical response at 2–4 week intervals

• Urea (40%): Breaks hydrogen bonds within stratum corneum keratin filaments, dissolving the intracellular matrix and disrupting corneocyte cohesion. At 40%, urea also increases stratum corneum permeability, facilitating deeper co-penetration of salicylic acid through the thickened keratin layer.
• Salicylic Acid (5%): A lipophilic beta-hydroxy acid that penetrates follicular and intercellular lipids. Exerts desmolytic activity by disrupting desmosomes (corneodesmosomes) linking adjacent corneocytes, reducing stratum corneum cohesion. Also solubilizes intercellular lipid lamellae, further loosening the compact hyperkeratotic layer. The combination of urea (aqueous-phase matrix disruption) and salicylic acid (lipid-phase disruption) provides complementary dual-mechanism keratolysis.

The urea 40% / salicylic acid 5% combination provides enhanced keratolytic efficacy compared to either agent alone and is appropriate for more resistant or extensive hyperkeratotic conditions including: plantar keratoses, palmoplantar keratoderma, ichthyosis, thick psoriatic plaques, and hyperkeratotic nail dystrophy. The synergistic dual mechanism is especially useful for thick, resistant calluses or plantar hyperkeratosis where single-agent therapy is insufficient.

Monitoring considerations:

• Monitor for irritation, burning, erythema, or excessive skin erosion at application sites
• Monitor for salicylate toxicity with large surface area applications (tinnitus, nausea, metabolic acidosis) in at-risk patients
• Diabetic patients with peripheral neuropathy: monitor closely for skin integrity
• Children and patients with renal impairment: limit application area due to salicylate absorption risk

Contraindications:

• Hypersensitivity to urea, salicylic acid, or any excipient
• Application to open wounds, broken skin, or infected skin
• Children under 2 years of age (salicylate toxicity risk)

Warnings & Precautions:

• Salicylate toxicity: avoid application to large surface areas, particularly in children, elderly patients, or those with renal impairment; systemic salicylate absorption can cause tinnitus, nausea, metabolic acidosis
• Avoid contact with eyes, mucous membranes, and healthy surrounding skin
• Use with caution in diabetic patients with neuropathy or peripheral vascular disease
• Salicylic acid increases photosensitivity; sun protection is recommended
• Urea and salicylic acid together may enhance the absorption of concurrently applied topical agents

Drug Interactions:

• Enhanced percutaneous absorption of co-applied topical agents due to combined barrier disruption
• Concurrent systemic salicylates: potential additive salicylate accumulation

Common Side Effects: Burning, stinging, erythema, and mild skin irritation at application sites. Excessive application or occlusion may cause skin erosion.

Store at room temperature (15–25°C); protect from excessive heat and freezing. Keep the container tightly sealed to prevent drying and oxidation. Use within the beyond-use date assigned by Genesis Compounding per 503A regulatory requirements.

Why combine urea and salicylic acid?

Urea and salicylic acid work through complementary mechanisms: urea targets the aqueous intracellular matrix of the stratum corneum, while salicylic acid targets the lipid intercellular junctions. Together they provide more complete keratolysis of thickened skin than either ingredient alone, which is especially valuable for resistant or thick hyperkeratotic conditions.

Can this be used on the feet?

Yes. This preparation is commonly prescribed for plantar hyperkeratosis, calluses, and keratoderma on the feet. Apply as directed, and use manual debridement of loosened skin if advised by your prescriber.

Is there a risk of toxicity from salicylic acid?

Salicylic acid can be absorbed systemically, especially if applied to large areas, under occlusion, or on broken skin. To minimize risk, apply only to the specific affected area as directed, not to large body surface areas. Report any symptoms such as ringing in the ears, nausea, or dizziness to your prescriber immediately.

How long will it take to see results?

Significant softening of hyperkeratotic skin is typically seen within 2–4 weeks of regular twice-daily use, though this varies depending on the thickness and type of hyperkeratosis being treated. Your prescriber will reassess at follow-up.

Is this FDA-approved?

This is a 503A compounded preparation by Genesis Compounding, prepared under a valid prescriber order for a specific patient. It is not FDA-approved as a compounded drug product.