The newest “diet pill” under study is actually a very old medication: sixty years old, as a matter of fact. And, it’s not even a diet pill: it’s an anti-histamine formerly marketed as Betahistine.

After learning that blocking the brain’s histamine-1 receptor causes weight gain, Tel Aviv-based nutrition expert Nir Barak went hunting for a drug that would stimulate that receptor.

He found Betahistine, which has been used to treat vertigo since the 1940s. Betahistine was pulled off the U.S. market in 1970 when the FDA began scrutinizing drugs more rigorously and demanded a new round of clinical trials.

Betahistine’s manufacturer, Unimed, never complied. A generic version is still sold in Europe, but the compound is no longer under patent protection in the United States.

That an anti-histamine could decrease appetite and reduce food cravings is no surprise to those of us who suffer allergies. After all, the old Dexatrim formula — the one that actually worked for many people — featured phenylpropanalomine (PPA) as its primary active ingredient.

Many overweight allergy sufferers — myself included — bemoaned the FDA’s decision to pull PPA from the market in 2000 due to the risk of high blood pressure with prolonged usage, leading to possible increased risk in strokes (as if being overweight doesn’t increase such risks, too).

Although Betahistine involves a different anti-histamine, it’ll be interesting to see if the FDA decides to block Betahistine’s development now that the “war on obesity” is receiving such great amounts of government attention.