The active ingredient in Nizoral is ketaconazole. In the US it is only available for 1% without prescription, in Canada up to 2% is available without prescription. I have used it and it does thicken the hair, however, the effect is only cosmetic and the 1% seems to work better at this than the 2%. The active ingredient is a mild anti-androgen, however I feel that DHT is not the root of the problem (pun intended). Niz contains sodium laureth sulfate, so it might irritate the scalp as much as it helps. The directions indicate to not use it too often. If you want to get rid of dandruff try taking a multi-vitamin, take 3000mg of a potent fish oil* (most crucial), some green tea extract, some grape seed extract, and 1000mg blackcurrant oil. That should thicken up your hair and get rid of dandruff and itching. If you want purely cosmetic suggestions then I can give you those too.