An Australian company will sell the world’s first armpit testosterone lotion in American stores next year after receiving approval from the US Food and Drug Administration, news.com.au reported Friday.

The lotion, created by Melbourne-based drug delivery firm Acrux, treats men with hypogonadism, a disease which produces low testosterone levels and includes symptoms such as erectile dysfunction, low sexual desire and performance.

Axiron — an anagram for “iron ax” — is the first testosterone replacement therapy to be applied in the armpit, with current treatments including a gel for the upper body and regular injections.

Only available by prescription, Axiron will be sold for the first time next year in the US, which has the world’s largest market for testosterone replacement, worth about $1 billion a year.

Acrux CEO Richard Treagus said: “What we’ve found is the population is aging in the US, Australia and around the world, and with [that comes] greater awareness around men’s health issues; more are now receiving treatment for them.”