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Along with facials, hair and scalp care are areas in which people are searching for natural remedies and care products. While homemade care products do exist, some uses for ingredients such as chili peppers and castor oil include trying to make hair grow. Proof is difficult to find. While that does not mean that they don’t have an effect, it does mean that claims of miraculous hair regrowth should be double-checked before you use these to try to thicken your hair into a glamorous mane with them.
Chili peppers are, of course, the peppers that you put in food to make it very “hot” or spicy. Many varieties of these exist, but they all contain varying levels of something called capsaicin. Castor oil is derived from the castor plant (Ricinus communis) and if you’ve ever watched television shows and cartoons from the mid-20th century, you’ve probably heard at least one character proclaim terror at having to take a spoonful of castor oil. It is used in laxatives, motor oil, nylon and dry-skin medications. The oil comes from the seeds of the plant, but note that the seeds themselves are poisonous. Palomar College says the poison does not leach into the oil, instead remaining in the leftover bean, but all the same, don’t attempt to make castor oil yourself -- leave it to those with the proper equipment and testing methods. You don’t want to risk bits of the leftover beans contaminating the oil.
The claims regarding chili pepper and castor oil for the scalp and hair sound good but aren’t really backed up by much in the way of research -- though there are some preliminary results. Beauty advice websites claim chili peppers make your hair start growing again and that castor oil can promote more hair growth in areas such as eyebrows, but they don’t provide the research to show that these substances actually do that. A couple of studies do exist that look at these clams, but what they found was a bit mixed.
A 2007 study in “Growth Hormone & IGF Research” looked at capsaicin -- this is what makes chili peppers hot -- and how it affects hair growth. The study looked at both mice and humans, and the humans had alopecia, which is a condition in which your hair falls out in clumps for no apparent reason. The researchers found that capsaicin might have an indirect effect on hair growth. When they gave the subjects capsaicin mixed with isoflavones, the same substances you find in soy that are supposed to be so beneficial, the human subjects had increased levels of “insulin-like growth factor-1,” which does affect hair growth, and those who had the actual mixture showed more progress than those who had a placebo. Note though that the subjects took pure capsaicin -- not chili peppers -- mixed with isoflavones in an oral dose. While this doesn’t mean that chili peppers placed on your skin wouldn’t have the same effect, it’s not proof-positive that they would. Something else in the chili pepper could always prevent the effect from happening, although even that hasn’t been investigated.
Castor Oil and Sapote
Castor oil has even less available research to back it up. Purdue University notes a mixture of castor oil and sapote seed -- sapote is a tropical fruit -- are used as a traditional hair tonic in Mexico, but there’s the possibility that the effect is because of the sapote and not castor oil. The university says a study from back in 1970 at the University of California at Los Angeles found sapote seed oil was able to stop hair falling out if the cause is seborrheic dermatitis. It’s possible the effects credited to castor oil may be due to sapote seed oil, at least in the Mexican tonic.