Although the new pill is very much in its early stages, it has passed the safety and efficacy preliminary tests.
According to Dr Wang, between four and six men experienced mild side effects like fatigue, acne or headaches.
Subjects took the drug or placebo once daily for 28 days.
The experimental contraceptive, 11-Beta-MNTDC, is a "sister compound" to dimethandrolone undecanoate, or DMAU, the first potential male birth control pill to undergo testing by the same research team.
It could still be 10 years before we see male oral contraception hitting our shelves.
For 28 days, 30 healthy men took the pill in one of two doses of 11-beta-MNTDC; 14 men received 200 milligrams and 16 took the 400-milligram dose.
The team, led by Dr. Stephanie Page of the University of Washington School of Medicine in Seattle, is planning longer studies of the drug, also known as 11-beta-methyl-19-nortestosterone dodecylcarbonate.
"Our results suggest that this pill, which combines two hormonal activities in one, will decrease sperm production while preserving libido", said Christina Wang, from Los Angeles Biomed Research Institute (LA Biomed). Pills, injections, patches, gels, intra-uterine devices; there's a wealth of misinformation and side effects, including messing with your mental health.
Those who took the pills saw a reduction in their hormone levels, suggesting their sperm counts had dropped.
"Since testosterone production is shut down in the testes, the androgen action in the rest of the body maintains "maleness" elsewhere, supporting things like male pattern hair, deep voice, sex drive and function, and lean body mass".
The outcomes of this trial were vastly different to a male birth control trial in 2016 that had to stop enrolling volunteers because so many men experienced side effects. The next step is to conduct longer studies, and, if the drug still proves effective, then larger studies studies will be carried out before testing the pill in sexually active couples.
None of them dropped out of the experiment or had less sex during the trial but some felt mild side-effects, researchers said. It could take about a decade for a male contraceptive pill to come to market.
Page told ENDO 2019 attendees plan to use the two oral drugs "in parallel in an attempt to move the [contraceptive medicine] field forward".