Neem as a contraceptive?

The use of neem as a contraceptive for both men and women has been “showing signs of early promise” ever since we started growing neem in 1992, but ongoing research has been somewhat sporadic. A new review article, published in the journal Phytomedicine, looked at the 341 articles published over the last 40 years and selected 27 to include after they met strict criteria for relevance, complete results and appropriate design.

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The full article is paywalled but the conclusion is clear: “Although A. indica is not reported with the complete alleviation of reproductive system in both male and female animal models, studies have proven its efficacy as a contraceptive. Extracts and phytochemicals from neem neither reduced the libido nor retarded the growth of secondary sexual characters, thus indicating only a temporary and reversible contraceptive activity. However, there is a dearth for clinical studies to prove the efficacy of A. indica as a herbal contraceptive.”

We had seen most of the studies over the years but some of the older publications were not online. One report we hadn’t seem, from the Central Ayurveda Search Institute for Drug Development, looked at using neem oil as a contraceptive in humans.

That study provided 246 women with 2 ml of neem oil in a plastic tube to use vaginally before having sex. Only nine pregnancies (3.65%) occurred over the 12- to 36-month study period, although 10% of women dropped out to use more modern birth control or avoid the “unpleasant odor of neem.”

What was particularly interesting about the review article was the way it looked at the different methods in which neem functioned as a contraceptive. The 27 reports are broken down by mode of action and the resulting changes in the test subjects’ physiology. It also outlines information on the part of the neem used — oil, leaf, bark or flower — as well as dosage given.

Another remarkable highlight from review: 14 of the 27 studies were conducted on males not females, perhaps marking a trend toward the long-awaited male birth control pill. (Except for the human study previously noted, most of the research was conducted on animals, primarily albino rats.)

Five of the reports showed neem functioning as an antispermatogenic in male rats. The different studies reported that sperm were less numerous or less mobile, smaller or had irregular shapes. In some cases, the diameter of seminiferous tubules was reduced. They were using either the leaf or the bark. Four of the studies used single oral dosages; one used a single subcutaneous dose.  

Antifertility was shown in three reports among both male and female subjects using leaf, oil and flowers. They responded to neem with fewer pregnancies and smaller litters. Three antiovulation reports indicate that neem interferes with the development of eggs in several ways, including the increased production of free radicals or proteins that cause egg cells to die.

Four reports documented hormone alterations, also seen in both male and female rats, using either leaf or oil in a single oral or subcutaneous dose. They generally affected the production of sperm and eggs, although estrogen, progesterone and testosterone were not changed.

Ten reports were categorized as “no-defined mode to achieve contraception.” In females, it inhibited pregnancy by interfering with ovulation and implantation. In males, including human sperm in a petri dish, mobility was diminished and sperm were damaged. In females, ovulation was disrupted or free radicals were released that disrupted ovulation.

In every report we could read, scientists called for more research. Since neem is widespread in many tropical locations, it could provide a much-needed option for impoverished countries. In rich countries, it could provide an alternative for men and women with virtually no side effects.

The problem is that clinical trials are expensive and they’re not likely to happen. It’s impossible to patent a tree and without the potential for long-term profit, no company can invest the millions of dollars needed for the large-scale study that would document its safety and efficacy. The researchers who compiled this review – biotechnology professors at Indian universities – hope that active ingredients can be identified and extracted to create a product that can be tested and clinically proven.

We do too!