Ouabain, a natural toxin so lethal it could take down an animal as large as a hippopotamus within minutes, is actually a suitable ingredient for male oral contraceptives.

Ethiopians have long used the glycoside as an arrow poison. It is commonly derived from two local plants, the Acokanthera schimperi, and Strophanthus gratus, and is also present among mammals which produce it at lower levels to regulate blood pressure.

The Use Of Arrow Poison

The traditional extraction process starts by boiling the roots, stems, leaves, and seeds of either plant over a fire. Arrow tips are then dipped into the concentrated liquid to make them poisonous.

However, ouabain is not all that dangerous. In 1859, English botanist Thomas Kirk noticed that his heart began beating stronger when he unknowingly used a contaminated toothbrush.

This accidental discovery unlocked the toxin's ability to trigger cardiac action, leading to its development into an effective treatment for heart conditions. Because of its potent properties, ouabain is currently a controlled substance.

Ouabain For Birth Control Management

Three years ago, a Chinese study already investigated ouabain's ability to impede the motility of sperm cells. Male laboratory rats were injected with the plant-derived form and the results were promising.

Despite its success, the toxin was never used to formulate male birth control pills. It was deemed too dangerous because of its known risks to the heart.

Recently, however, a new study has yielded the same results but the scientists behind it used a modified analog of the glycoside. They tampered with its molecular arrangement by removing a sugar group and replaced its lactone group with a triazole group to render it as non-toxic to the heart and other systems of the human body.

The team reports that in male rats, the ouabain derivative only affected sperm cells by binding to a subunit known as Na,K-ATPase α4. It reduces the ability of sperm cells to swim, effectively producing male infertility.

The results of this study contribute significantly to the development of a working male pill, most especially that the toxin's effects on sperm function were found to be temporary.

Injectable Hormonal Contraceptive For Men

With limited birth control options available for men, scientists have been trying to create not only oral pills but also hormone injections.

Last year, scientists created a formula made of 200 mg norethisterone enanthate combined with 1,000 mg testosterone undecanoate. It was injected on male participants every eight weeks.

The German team concludes that the hormone injections were effective in suppressing the production of sperm cells and that such effect was reversible even after 52 weeks of using the contraceptive.

However, the hormone injections were terminated because they brought on side effects such as acne, increased libido, and mood disorders.