NAC (N-Acetyl Cysteine) is a modified form of cysteine--a sulfurous amino acid that if taken regularly can aide in hair growth along with other health benefits. NAC is available in supplement form but can be found in foods such as brussel sprouts, broccoli, eggs, fish, garlic, seafood and whole grains. The benefits of NAC are optimized when taken with vitamin C.

NAC is processed through the liver in the body and acts as a powerful antioxidant in several areas of the body. Cysteine supplements are not safe to take for a long period of time because of it's tendency to convert to cystine in the body which can result in kidney and bladder stones. NAC as a modified version is safer to take for longer periods of time continuously and is found to be a more potent form of the amino acid than cysteine by itself.

The body does not produce sulfur on it's own but it is a necessary nutrient for the health of your hair. Therefore, it is vital to receive this mineral in the body through diet and/or supplements such as NAC--which is a sulphurous amino acid. A sulfur deficiency can cause the hair to be weak and brittle and experience slow growth. Taking NAC supplements or incorporating the foods that carry the nutrient will bring back luster, strength and healthy growth of the hair by supplying the much needed sulfur to your blood stream.

NAC can be found in a supplement at most vitamin and health shops but can also be found in certain foods in your grocery. Whole eggs are the most natural and potent carrier of this amino acid as an alternative to taking supplements. The benefits of NAC can also be experienced by eating greens such as brussel sprouts and broccoli as well as peppers, garlic, fish, whole grains and whey protein.

Although NAC is a more stable form of cysteine by being less likely to convert to cystine and cause kidney and bladder stones, the likelihood--even though small--is still present. As recommended by Advanced Health and Life Extension, taking two or three times the amount of vitamin C of your NAC dosage will help the supplement continue to work as an antioxidant rather than an oxidant.

It is recommended to start off with a small dosage of NAC supplements eventually working your way up to higher dosages to avoid digestive problems. According to Vita Viva-Info, it is recommended to start off with 500 milligrams a day for the first week slowly increasing with your consistent use. You can safely take up to 12 grams of NAC supplements twice daily to see a decrease in hair loss and increase in hair growth.

According to the American Academy of Anti-Aging Medicine, should you have an allergy to eggs, dairy products or taking diabetic medication you should not take the NAC or cysteine supplement as you may experience severe headaches.