Dr. Merritz nail fungus lacquer: composition and application rules

Nail fungus does not go away on its own: the nail plate turns yellow, flakes, and thickens over months. Ointments and medicated nail lacquers help, but they require consistency, which is why many people abandon the course halfway through.

According to NICE, in Europe and the US the infection occurs in 4.3-8.9% of adults (as of 10/2026). Athletes have a 2.5 times higher risk. Below we take a closer look at Dr. Merritz nail lacquer: what the company claims about its formula, how it is used, and what it does not replace.

What nail fungus is

💡 In short:

• Nail fungus affects the nail plate: the nail changes color, flakes, and thickens.
• The company describes Dr. Merritz lacquer as a product with antifungal ingredients and nail care benefits.
• Results depend on three things: regular application, dry nails, and personal tools.
• Undecylenic acid as an antifungal agent: 10/2026, according to Mayo Clinic.

Nail fungus, or onychomycosis, develops gradually. First the color changes, then the plate loses density and thickens. It is often preceded by athlete's foot that was not fully treated.

The infection thrives in warmth and moisture. Closed shoes, swimming pools, shared locker rooms, and other people's towels increase the risk. People with diabetes and weakened immune systems may have a more severe course, and they should not delay seeing a doctor.

That is why treatment stretches over months. If you stop using the product in the second week, the fungus will return to its previous extent. The nail plate simply does not have time to grow out clean.

What is claimed about Dr. Merritz lacquer

Dr. Merritz lacquer is presented on the website ichbinpharmazeut.com. According to the product description, it is a product that combines antifungal ingredients and nail care in a single bottle.

According to the product description, the lacquer is applied like regular nail polish: a thin layer on a clean, dry nail plate. The claims include easy application, fast drying, and a neat nail appearance.

Separate fact from promise. The product itself does not replace a doctor's visit; it only complements care. Check the ingredient list on the packaging and confirm whether the formula suits your situation.

Formula: what is known about the ingredients

The formula is based on undecylenic acid. According to Mayo Clinic, it belongs to the antifungal agents and is sold over the counter, but it is largely inferior to newer medications (10/2026).

In addition, the company claims tea tree oil as an antiseptic, vitamin E to nourish the nail plate, and lavender and peppermint essential oils for a fresh scent.

What this means for you: the ingredient list is described by the manufacturer, not by an independent study. This does not rule out using the product, but it lowers expectations.

How to use the lacquer

The schedule is set by the manufacturer, and it should be followed exactly. The general process is as follows:

• Prepare the nail: trim, file, and wash it.
• Apply the product to a dry, clean nail plate in a thin layer.
• Let it dry completely before putting on socks and shoes.
• Repeat the procedure according to the instructions, without long gaps.
• Compare the nail's condition using recent photos.

Consistency matters more than strong nails at the start. If you apply the product only occasionally, the effect is lost. Do the procedure at the same time every day, for example in the evening, so you do not skip it in the daily rush.

Do not expect a miracle right away. A toenail grows out slowly, so you should judge by the new edge at the base, not by the old spot. Compare the condition with photos every couple of weeks, and you will see the progress.

Hygiene and care to keep the fungus from returning

While treatment is ongoing, remove the conditions in which the fungus thrives. These steps are simple, but they determine whether the infection returns or not.

• Wash and thoroughly dry your feet, especially between the toes.
• Do not use other people's files, clippers, or towels.
• Let shoes dry out for a full day, and use removable insoles.
• Wear socks made of natural fabrics and change them every day.
• Wear your own flip-flops at the pool and in the shower.

Shoes and socks matter no less than the lacquer itself. Tight shoes trap moisture, and a moist environment helps the fungus grow. Give your feet some air at least at home, and the risk of recurrence drops noticeably.

A shared towel and other people's tools quickly lead to reinfection within a household. Give each family member their own clippers and keep them separate. That way you protect both your loved ones and yourself.

When the lacquer will not help

Not every nail change is related to fungus. Darkening after an injury, psoriasis, and age-related changes look similar. Only a specialist can determine the exact cause, sometimes with a scraping.

See a doctor if the nail hurts, becomes inflamed, or develops dark streaks. With diabetes or a weakened immune system, do not delay the visit. Such cases cannot be solved with a lacquer.

This material is for informational purposes only and does not replace a consultation with a specialist.

⁉️🤔 Frequently asked questions

Does Dr. Merritz lacquer help with nail fungus?

It depends on the case. The company claims antifungal properties, but the treatment plan and the fact of treatment itself are determined by a doctor. The lacquer is convenient to use and masks the defect. However, long-standing and severe forms are more often treated with systemic medications.

How long until results appear?

A toenail grows out slowly, so noticeable changes do not come immediately. Look at the new edge at the base, not at the old area. If after several weeks there is not even slight clearing, go back to the doctor.

Can the lacquer be applied over decorative nail polish?

No. The product is applied to a clean, dry nail plate without old polish. First remove the coating, wash and dry the nail. Only then apply the treatment layer; otherwise the product will not reach the nail plate.

What should I do if the nail hurts or bleeds?

You should go to a doctor, not to the bottle. Pain, swelling, and bleeding cannot be solved with a topical product. Self-treatment in such a case can make the condition worse. An examination and, if necessary, a scraping will give an accurate picture.

Does the lacquer replace a visit to a specialist?

No. The lacquer can be considered part of nail care, but not a replacement for a diagnosis. A doctor assesses the type of pathogen and chooses a strategy. Without that, any product remains supplementary.

In short: what to check before buying

Dr. Merritz lacquer is designed for those who are ready for long-term, consistent care and want to combine it with treatment. If the nail hurts, is severely deformed, or you have not seen a doctor in a long time, start with a consultation.

• Mild form, you have patience: the lacquer works only as part of care and with a strict routine.
• Pain, inflammation, diabetes: see a doctor first, lacquer care later.
• Prevention in the household: personal tools and dry feet matter more than a bottle.

Before buying, check the ingredient list, expiration date, and instructions on the packaging. One bottle does not replace the entire care system.