Straightening and Smoothing Shampoos
Shampoos that claim that they'll straighten or smooth your hair generally have a coating ingredient in them.
"It's usually silicones...[or] oils," Acord says. "They will aid in coating the hair, and allowing hot tools to straighten and/or smooth it out."
What about the shampoos that claim to give your hair more volume? Most of them are formulated to open the hair's cuticle, making it thicker, Acord says. "But that, too, can damage the hair, and it will also remove color as well as reversing perms and relaxers."
No shampoo is going to make hair lighter and fluffier, O'Brien says. "Your best bet for more volume is a shampoo that has a nice, lightweight conditioning agent that rinses off really well."
But most people don't pick conditioners that do that. "The consumer wants something we in the industry call 'slip' -- that slippery, smooth feel you get from your hair after you rinse the conditioner out," O'Brien says. "But feeling 'slip' doesn't mean it's helping your hair. In fact, it means the conditioner is staying on your hair, and you don't want it to stay."
"Clarifying" sounds clean and clear -- but they can be rough on your hair, O'Brien says.
"Very few people will really need a clarifying shampoo," he says. They're generally used because someone has some kind of condition or is going to get a chemical treatment, and they really need to cleanse the hair. They rough up the hair's cuticle, for example, so the perm or color might take better. But some of them can be extremely harsh."
You should definitely avoid clarifying shampoos aftergetting your hair colored. "Even the mildest clarifying shampoos will unwind that color really fast," O'Brien says.
Shampoos for Color-Treated Hair
These shampoos are made to help make your color last. Acord recommends checking on the shampoo's "ph" level, which is a measure of how acidic or alkaline the product is. He suggests looking for a ph between 4.5-5.5 to help prevent fading. If the ph level isn't shown on the shampoo bottle, try searching the product's name and "ph level" online.
Good shampoos for color-treated hair may also use an ingredient like an oil, sea kelp, or algae to help color stay in your hair, O'Brien adds.
Want to refresh your hair without a full shower and blow-dry? Try a dry shampoo.
"They can really be a lifesaver and break that every day shampoo habit," O'Brien says. "Pump a burst [of dry shampoo] down your hairline, in the part, and at the crown, and take your blow dryer and brush and fluff it up, and you're probably out the door in five minutes."