Why over-the-counter nail lacquer sometimes does not clear nail fungus

It is one of the most repeated stories at the clinic: “I have been using a lacquer for a year and the nail is exactly the same.” And there are usually three reasons behind it, none of which is that the product is a scam.

They are worth understanding, because all three can be corrected.

A yellowish, thickened or lifting nail is not necessarily onychomycosis. It may be the consequence of an old knock —sometimes years earlier—, of continuous pressure from short footwear, of psoriasis, or of other nail conditions.

An antifungal applied to something that is not fungal does nothing, and months are lost while it is being used. That is why the first step is not to treat: it is to find out what it is.

If what you see is a nail that has turned black without an obvious knock, black toenail without a knock explains what to watch for and when to get it checked.

The fungus lives within the thickness of the nail and underneath it, not only on the surface. The thicker and more affected the nail, the harder it is for a topical treatment to reach it. How well it works depends on a correct diagnosis, on how much of the nail is affected, on the product and on applying it for as long as needed.

That is where the part you cannot do at home comes in: reducing the thickness of the nail and removing the damaged portion. It is not cosmetic: it helps a topical treatment reach the problem better.

A toenail takes months to renew completely. That means that even if the treatment works from day one, the already damaged part does NOT heal: it is replaced as new nail grows.

With that expectation, it is logical to conclude after two months that it is doing nothing. The way to know whether it is working is not to look at whether the discoloured patch fades, but whether the nail emerging from the base comes through healthy.

If the nail has changed in thickness or colour, if it bothers you when walking, or if you have spent months on a treatment without seeing healthy new nail coming through. And before that if you have diabetes or circulatory problems: in that case a thickened nail pressing on the skin is not simply a matter of appearance.

Fungal and bacterial infections explains how a fungus is told apart from other nail changes at the clinic, and how treatment and follow-up are planned.

If what worries you is not the nail but the skin —itching or flaking between the toes—, itchy skin between the toes explains what it may be and when to get it checked.