Most shampoos fall into the moisturizing category, meaning they contain ingredients like silicone and protein designed to soften the hair and lock in moisture. Unfortunately, these conditioning ingredients can build up over time, weighing down the hair and leaving it dull and limp. Styling products like gels and mousses can also leave residue behind.
For this reason, some experts recommend using a deep-cleansing shampoo, also known as clarifying shampoo, once a week to remove buildup. Clarifying shampoos contain the same basic ingredients as other shampoos, except they have slightly higher dosages of cleansing detergents and no conditioning additives. Julyne Derrick, the About.com guide to beauty, notes that you can also remove product buildup by rinsing once a week with a mixture of 1 part apple cider vinegar and 2 parts water. However, she warns that this DIY formula, like most clarifying shampoos, can strip away the dye from color-treated hair.
Overall, the most popular clarifying shampoo in reviews is Neutrogena Anti-Residue (Est. $5 for 6 oz.). Thousands of users at Makeup Alley, Amazon.com, and Drugstore.com give this shampoo high overall ratings. Reviewers say it does an excellent job of removing oil and residue from the hair and scalp (the phrase "squeaky clean" comes up repeatedly in reviews) and leaves hair soft and shiny. Some users even note that it cured their dandruff, possibly because it was due to irritation from product buildup. Most users like the scent, which is generally described as woodsy or herbal, although a few find it too strong. One caveat we saw from many reviewers is that this shampoo is only meant to be used once a week; more frequent use can leave the hair too dry.
Suave Naturals Daily Clarifying (Est. $8 for 22.5 oz.) also fares well in user reviews, although its ratings aren't quite as high. Users say this shampoo does a great job of deep cleaning the hair and scalp, but they're split over how harsh it is to the hair. The majority of users say that, as its name suggests, this shampoo really is gentle enough to use every day, leaving hair soft and manageable. However, a significant number aver that it's too drying for daily use and should only be used once a week at most, followed by a good conditioner. Also, like Neutrogena Anti-Residue, this Suave shampoo got mixed reactions for its scent. Descriptions of the fragrance range from clean and fresh to musky to flowery, and users seem to either love it or hate it.
Overall, the Neutrogena and Suave clarifying shampoos are very similar in their benefits. We're naming Neutrogena as our Best Reviewed pick because it's slightly more popular with users, but the choice between them could easily come down to a matter of which fragrance you personally prefer.
One drawback of clarifying shampoos is that they're not safe to use on color-treated hair. Fortunately, according to Derrick, there's another, gentler option for cleaning and refreshing the hair: baby shampoo. This type of shampoo is specially formulated to be free of ingredients that could irritate a baby's delicate skin and eyes. However, many users say they're just as handy for adults with sensitive skin, who might find most shampoos too harsh to use on a daily basis.
Johnson's Baby Shampoo (Est. $12 for two 20 oz. bottles) is a classic "tear-free" formula that gets high marks from hundreds of users at Amazon.com, Drugstore.com, and Makeup Alley. Some use it for their children's hair, some for their own, and some for other purposes altogether, such as bathing pets or cleaning makeup brushes. Reviewers say Johnson's shampoo is gentle yet effective, particularly for fine or oily hair. It leaves hair soft, adds body, and has a pleasant, mild scent. Surprisingly, several users also say that this shampoo helped with their dandruff, even though it doesn't contain any specific dandruff-fighting ingredients. As a bonus, many users find this baby shampoo makes a good face wash that combats acne.
Some reviewers on Amazon.com and Makeup Alley express concern over whether Johnson's Baby Shampoo is truly nontoxic. One ingredient they mention in particular is quaternium-15, a formaldehyde-based preservative. However, that ingredient was removed from the product in 2014. Some also say that the shampoo's artificial fragrance can be irritating to the skin or eyes, though Johnson's claims that its baby shampoo is "dermatologist-tested" and "clinically proven hypoallergenic."
We also found good overall reviews for Mustela Baby Shampoo (Est. $11 for 6.8 oz.). This shampoo boasts on the label that 93% of its ingredients are of natural origin and that it's hypoallergenic, gentle on eyes and skin, and free of parabens, phthalates, and phenoxyethanol. Reviewers at Amazon.com and TotalBeauty.com agree that the shampoo is indeed gentle, cleans babies' hair effectively, and helps with skin problems such as eczema and cradle cap. Most users describe the scent as light and fresh, although a few find it medicinal.
The main drawback of Mustela Baby Shampoo is that it costs over four times as much as Johnson's. Moreover, there's no real evidence that it's any safer, and like Johnson's, it, too, contains artificial fragrance.