Over 75% of Ayurvedic remedies contain neem, usually in form of leaf (or extract), sometimes the bark/fruit/flowers, and almost never the oil.
The leaf is also the part of the neem plant that western medicine knows the most about. The majority of scientific neem studies was done with neem leaf or neem leaf extracts.
Neem oil is neem seed oil, not neem leaf oil as some people wrongly assume. It can be made safe for consumption, and especially the use of neem oil for birth control (as a “male pill”) continues to generate a lot of interest. However, it really needs special knowledge and treatment before neem oil can be taken internally.
Not so for the leaf. Neem leaves are considered safe to take internally on a regular or daily basis (provided you aren’t pregnant or trying to conceive. See neem contraception.) In the thousands of years that people across India have been taking neem there have never been any reports of negative side effects from leaves.
Of course, you should still use common sense, as you should with any herbs. Start by trying a little to make sure you don’t show any allergic reaction, and generally don’t overdo it. As magical as all the medicinal properties sound, neem is not a magical cure all that will simply fix anything if you just take enough… But it can help with a lot, if taken sensibly.
In 2005 scientists published a research report, Medicinal properties of neem leaves: a review. It is a compilation of existing scientific studies and clinical trials. It shows very impressively just how versatile the leaves are. Here is what it says about the benefits of neem leaves:
“Neem leaf and its constituents have been demonstrated to exhibit immunomodulatory, anti-inflammatory, antihyperglycaemic, antiulcer, antimalarial, antifungal, antibacterial, antiviral, antioxidant, antimutagenic and anticarcinogenic properties.”
Is taking neem leaves safe?
Simple quick answer for the impatient: Yes.
In thousands of years of traditional medicinal use, and tens of years of scientific studies, fresh or dried neem leaves have never hurt anyone or anything.
However, different people have different reactions to substances, whether drugs, foods, or herbs. Also, depending on what else you are taking there may be unexpected interactions. If you take neem for the first time, take only a little, and see what happens. You may just be the first person ever to have a neem allergy…
Neem leaf extracts and tinctures: if a plant contains toxic substances, then these are usually concentrated in tinctures and extracts. Different extracts will contain different concentrations of different ingredients, depending on the solvent used and the method of processing.
Neem extract is mostly known for its promising medicinal uses, but in some experiments neem leaves extracts have produced nasty side effects in laboratory animals. Unless you know exactly what you are taking and what you are doing, don’t self medicate with extracts. The use of extracts should be left to experienced Ayurvedic doctors