Dandruff is a common condition characterized by white skin flakes throughout the hair. According to the Mayo Clinic, it can pop up for various reasons, including simple dry skin, sensitivity to hair products, fungal infection, and seborrheic dermatitis, which causes oily, irritated skin on the scalp. Dandruff shampoos use a variety of ingredients to combat these problems. Some contain antifungal agents, such as zinc pyrithione and ketoconazole, to kill the fungi that can cause dandruff and seborrehic dermatitis. Others combat skin flaking by slowing the rate at which skin cells die and peel off.
Because dandruff has different causes, you may need to try several different products before finding the one that does the best job of controlling your dandruff. If you've tried several over-the-counter shampoos and nothing seems to work, or if you have symptoms like intense scalp itching or burning, talk to a doctor; you may need a prescription-strength anti-dandruff shampoo, or possibly a steroid cream.
The dandruff shampoo that most consistently works for reviewers is Nizoral (Est. $14 for 7 oz.). Its main dandruff-fighting ingredient is ketoconazole, an antifungal medication that experts say often works when other treatments fail. Consumers at Amazon.com, MakeupAlley.com, and Drugstore.com consistently give Nizoral high overall ratings, saying it's very effective not just for dandruff but also for other skin conditions that affect the scalp, like eczema and psoriasis. Many users say they tried every dandruff product on the market, and Nizoral was the only one that worked for them. And, in addition to clearing up dandruff, users say this shampoo generally does a good job getting the hair and scalp clean. As a bonus, some users say that since they started using Nizoral, their hair has actually become thicker and stronger. Beauty expert Paula Begoun agrees, recommending Nizoral specifically to combat hair loss.
Nizoral does have its disadvantages, however. For a start, it's much more expensive than most dandruff shampoos on the market. Also, many reviewers say it has an unpleasant, medicinal smell, and some complain that it's harsh and drying to the hair. Some users also worry about the safety of the powerful antifungal agent in Nizoral, though expert feedback indicates that used topically, ketoconazole is relatively safe. In any event, most are happily willing to deal with those tradeoffs in exchange for an effective dandruff treatment.
However, for those who don't want to pull out the big guns right away, there are other dandruff shampoos on the market that are less powerful, but also less expensive. One of the best known is Head & Shoulders Classic Clean (Est. $11 for 33.8 oz.), which gets high ratings from users at Amazon.com, Drugstore.com, and TotalBeauty.com. Users say this shampoo does a good job on dandruff, lathers well, and smells better than most dandruff shampoos. However, even though users find it gentler than other dandruff shampoos, they still say it can be drying and recommend using a separate conditioner for added moisture. Although zinc pyrithione, the active ingredient in Head & Shoulders, isn't as consistently effective as ketoconazole, it works for many users and costs much less.
If neither Head & Shoulders nor Nizoral works for you, one product that might offer relief is Neutrogena T/Gel Dandruff Shampoo, Original (Est. $16 for 16 oz.). Neutrogena contains coal tar, which combats skin flaking by slowing the turnover rate of skin cells. Users at Amazon.com and Drugstore.com say this product is very effective against dandruff and eczema, even when every other product – including Nizoral – has failed. On the downside, users consistently find that this shampoo smells terrible – reviews compare it to motor oil, mothballs, and burning rubber – and that it can be very harsh and drying.