Natural hair loss prevention appeals to many men who are coping with hair loss. Medical treatments often have side effects that can be bothersome or even frightening. But natural hair loss prevention has a reputation for being safer, and if it doesn't require a trip to a doctor, then it's all the more appealing. Two of the main natural treatments for hair loss are saw palmetto extract and nettle root extract.
The main goal of these two natural treatments for male pattern hair loss is to reduce levels of a substance called DHT. DHT is made from testosterone, and when it is found in large concentrations in the scalp, there is usually the typical male pattern hair loss. There are prescription drugs (Propecia and its generic equivalents) designed to inhibit the formation of DHT, and while many men say the results are great, many do not, and many men suffer greatly from side effects from these drugs (though serious side effects are rare).
Saw palmetto, which is native to North America, is an herbal DHT inhibitor that does not result in the serious side effects attributed to Propecia. Saw palmetto has been used for hundreds of years by native Americans for treatment of urinary disorders in men, and it is considered effective in treating enlargement of the prostate gland. Because it blocks an enzyme called 5-alpha reductase, which converts testosterone in to DHT, it could have the effect of slowing, stopping, or even reversing hair loss, though the results will of course vary by individual.
Some research has shown that nettle root, particularly when used in conjunction with pygeum (another herb) extract partially blocks two enzymes. One is 5-alpha reductase, which makes DHT, and the other is aromatase enzyme, which makes estrogens. Together the two work better than either one alone. Nettle root is effective at higher concentrations, while lower doses are pygeum were most effective. These have been combined in an herbal product called Prostatonin that is used to treat benign prostate enlargement, and which theoretically could have a positive effect on hair loss.

Natural hair loss prevention has many approaches. For those who may not have a very nutritious diet, vitamin supplements, particularly those rich in B vitamins containing biotin, inositol and niacin may be a good idea. They aren't harmful except in excessive dosages. Gentle hair care can be helpful, because harsh chemical treatments such as permanent hair color can be hard on hair, resulting in breakage, which can add to the appearance of thinner hair. Gentle scalp massage, and regular exercise are two ways of improving circulation to the scalp. While these measures may not stop hair loss, and aren't scientifically proven to grow hair where it wasn't growing before, they can help people who are experiencing hair loss to hold onto the hair they have and keep it as healthy as possible.