The same chemicals that create that sometimes overwhelming scent are what make these herbs helpful for many medical conditions, including sexually transmitted diseases. Some of the earliest scientific studies on these herbs proved that water-based extracts from Lemon Balm can kill the herpes virus. Follow up studies found that many other herbs in the Lamiaceae family were able to do the same.
Overall, these herbs have been shown to kill a variety of virii, fungi and bacteria in the right circumstances. No one has yet proven whether or not they will kill infections inside the body, but they are definitely effective outside the body.
Unsurprisingly, someone eventually decided to test whether or not peppermint, lemon balm and sage would be effecting against HIV. In 2008 A team led by Silvia Geuenich at the University of Heidelberg tested the effect of water-based extracts on HIV both in test tubes and human tissue. It turns out that herbal extras from these three herbs do indeed interfere for HIV. Even better, the ‘dose’ needed for them to interfere with HIV is low enough that is does not hurt the cells of the body.
Skipping the scientific jargon, something in the extracts from the Lamiaceae family members interferes with the way HIV connects with cells. After the virus has attached to a cell it is to late for the herbs to have effect. The extracts were tested up to point of being 50% effective in stopping HIV from infecting cells.
What does this mean for people with HIV/AIDS? At this point, it is too early to say if any of these herbs will have an effect on HIV/AIDS inside the body, but it is possible. While it isn’t safe to ingest pure extracts, it is possible that drinking teas or tinctures made from peppermint, lemon balm and sage could interfere with the rate at which HIV infects white blood cells, slowing the rate at which the viral load increases.
However, there is another use for these herbs in fighting HIV. Prevention. As Dr. Geuenich’s team concludes in their research paper, these herbs show good possibilities as a topical microbicide to protect against STDs. Extracts from these plants should never be applied directly to the skin, they are too strong. In the study the extracts were effective against HIV in solutions of less than 5%. While these extracts are not effective enough to negate the need for condoms, they may be useful as a backup for condoms, for instance if someone formulated a lubricant with a low percentage of one of these extracts. Anyone who is considering using extracts from peppermint, lemon balm or sage should speak with a doctor and trained herbalist to make sure they are doing so safely.