What is Avoca Used For?: An Examination of the Silver Nitrate Treatment

October 7, 2025 •

5 min read

Did you know that silver nitrate, the active ingredient in Avoca, has been used in various medical applications for centuries due to its powerful caustic and antiseptic properties? This over-the-counter medication specifically leverages this compound to treat common skin growths, making it vital to understand what is Avoca used for before application.

Quick Summary

Avoca, a topical treatment containing silver nitrate, is used for chemically cauterizing and removing warts, verrucas, and excess granulation tissue. The product is applied directly to the affected area to destroy the unwanted tissue.

Key Points

Wart and Verruca Removal: Avoca is primarily used to remove common warts on the hands and verrucas on the feet by destroying the affected tissue.
Granulation Tissue Cauterization: It is also used in wound care to treat and remove excess granulation tissue, which can hinder the healing process.
Active Ingredient is Silver Nitrate: The medication contains silver nitrate, which works by chemically cauterizing the unwanted skin cells.
Causes Temporary Skin Staining: A common side effect is a temporary, harmless black or brown staining of the treated area and any surrounding skin contacted by the solution.
Requires Careful Application: Using Avoca involves precise application with a moistened stick, protecting healthy skin with petroleum jelly to prevent burns and staining.
Not for Use on Sensitive Areas: Avoca is not for use near the eyes, on genital warts, or on other sensitive parts of the body due to its caustic nature.
Home Treatment Takes Multiple Days: A course of treatment for warts may last 3 days, while verrucas can take up to 6 days, with filing required between applications.

The Primary Uses of Avoca

Avoca is a brand name for a topical treatment that primarily utilizes silver nitrate for its caustic effects. The medication is available in the form of pencils or applicator sticks, which allows for precise application on targeted areas of the skin. The main therapeutic uses of Avoca include:

Wart Removal: Warts are small, rough growths caused by the human papillomavirus (HPV). Avoca is designed to destroy the tissue of common warts, most often found on the hands.
Verruca Treatment: Verrucas are plantar warts that occur on the soles of the feet. Avoca provides an effective, at-home method for eliminating these stubborn growths. Treatment duration for verrucas is typically longer than for common warts.
Granulation Tissue Management: In wound care, excessive granulation tissue (also known as proud flesh) can sometimes form and impede healing. Avoca is clinically used to cauterize and remove this unwanted tissue, helping to normalize the wound bed and promote a more optimal healing process.
Removal of Unwanted Skin Growths: Beyond warts and verrucas, Avoca can be used to remove other minor, unwanted skin growths, though this should always be done under proper medical guidance.

How Avoca Works: The Science of Silver Nitrate

The effectiveness of Avoca stems from its active ingredient, silver nitrate, which has strong cauterizing properties. When the tip of the applicator stick is moistened with water and applied to the skin, the silver nitrate reacts with the proteins in the tissue. This reaction effectively destroys the unwanted tissue layer by layer.

The process works by chemically burning away the affected skin cells. The treated area will typically turn black shortly after application as the silver nitrate oxidizes and destroys the tissue. Over a few days, the dead, blackened skin will scab and fall away, revealing healthy skin underneath. For persistent warts or verrucas, the application may need to be repeated after filing away the dead skin.

A Step-by-Step Guide to Using Avoca

Using an Avoca applicator requires careful attention to the instructions to protect healthy skin and ensure effective treatment. Here is a general guide:

Preparation: Gather a small amount of clean water, a non-absorbent surface (like an upturned glass), a tissue, and petroleum jelly.
Protect Healthy Skin: Apply a thin layer of petroleum jelly around the wart or verruca to shield the surrounding healthy skin from the caustic effects.
Activate the Stick: Put a single drop of clean water onto the non-absorbent surface. Place the tip of the Avoca stick into the water droplet and gently swirl it for about 20 seconds to activate the silver nitrate.
Application: Using the moistened tip, transfer the liquid to the surface of the wart or verruca. Do not rub or apply pressure, as this can cause the tip to break.
Drying: Allow the treated area to dry completely before any contact with surfaces or clothing. The area will turn black over time.
Follow-Up: After 24 hours, use a fine emery board or coarse nail buffer (often included in treatment packs) to file away the dead, blackened surface tissue.
Repeat as Directed: Repeat the application process daily for the recommended duration (e.g., 3 days for warts, 6 days for verrucas), or until the lesion is gone.

Comparing Avoca with Other Wart and Verruca Treatments


Feature	Avoca (Silver Nitrate)	Salicylic Acid Preparations (e.g., gels)	Cryotherapy (e.g., freeze spray)
Mechanism	Chemically cauterizes and destroys tissue layer by layer.	Chemically dissolves keratin, peeling away the wart.	Freezes the wart tissue using a cold agent, causing blistering and removal.
Application	At-home application using a moistened caustic pencil or applicator stick.	At-home application of a gel, liquid, or patch over a period of time.	At-home application using a freezing device or in-clinic treatment by a professional.
Timeframe	Results often visible within a week, but multiple applications over several days are needed.	Can take several weeks of consistent, daily application to see results.	Often effective in one or a few sessions, but can be more painful.
Precautions	Must protect healthy skin with petroleum jelly; can cause temporary black staining; do not use near eyes or on sensitive areas.	Requires protecting surrounding skin; can cause irritation if not contained; may not be suitable for all skin types.	Can cause blistering and discomfort; may require multiple sessions for complete removal.
Effectiveness	Clinically effective for many warts and verrucas.	Effective for many common warts, with proven clearance rates.	High success rates, particularly in professional settings.

Important Safety Precautions and Side Effects

As a caustic agent, Avoca must be used with caution to prevent injury to healthy skin. Key precautions include:

No Genital Warts: Avoca should never be used on genital warts.
Avoid Sensitive Areas: Do not apply Avoca near the eyes or on other sensitive parts of the body.
Risk of Staining: Silver nitrate will cause a temporary, harmless black or brownish stain on the treated skin that fades over several days. It can also permanently stain fabrics, furniture, and countertops.
Potential for Side Effects: Common side effects include mild skin irritation, redness, or a burning sensation during and after application.
Risk of Argyria: Long-term, chronic use on open wounds or mucous membranes can lead to argyria, a permanent bluish-black discoloration of the skin due to silver deposition. This is very rare but highlights the need for careful use.
Ingestion Risk: Avoca is toxic if swallowed. Keep it out of reach of children and pets, and seek immediate medical attention if accidentally ingested.

Conclusion: Is Avoca the Right Choice for You?

Avoca offers a fast and effective over-the-counter solution for the removal of common warts, verrucas, and granulation tissue through its powerful silver nitrate formula. Its easy at-home application makes it a convenient option for many individuals. However, as a caustic treatment, it requires careful and precise application to avoid harming surrounding healthy skin and causing temporary staining. For those with persistent symptoms or questions, a healthcare professional should be consulted. A thorough understanding of Avoca's uses, proper application technique, and safety precautions is essential for a successful treatment outcome. For more detailed clinical information, one can consult the DailyMed entry on Avoca.

Frequently Asked Questions

To use Avoca, moisten the tip of the stick with a single drop of clean water on a non-absorbent surface. Apply a thin layer of petroleum jelly around the affected area to protect healthy skin. Gently transfer the liquid from the tip to the wart or verruca. File away the blackened, dead skin after 24 hours.

The active ingredient in Avoca is silver nitrate, which is a powerful caustic agent used for chemically destroying unwanted skin tissue.

Yes, Avoca contains silver nitrate, which causes the treated area to turn black or dark brown over a short period of time. This staining is temporary and harmless, and it fades as the dead skin sheds.

No, Avoca must not be used on genital warts or any other sensitive areas of the body due to its strong caustic properties.

For warts, the recommended treatment is to apply Avoca once daily for 3 days. Results are often visible within a week, as the treated tissue dies and is filed away.

If Avoca accidentally touches healthy skin, immediately wash the area with a saline solution or large amounts of plain water. The skin may still experience some staining, but this will fade as the outer skin layers regenerate.

Yes, potential side effects include mild skin irritation, redness, burning, peeling, and temporary black staining of the skin. Severe or prolonged use can lead to argyria, a permanent bluish-black discoloration.

Avoca is generally considered safe for use on children under adult supervision when applied as directed. For very young infants, the lower-strength 40% product is often preferred by healthcare professionals.