Mousse, Gel, Serum, or Leave-in Conditioner: Which Product Should You Apply After You Wash Your Hair?

Hair wash routines can be pretty standard: Shampoo, condition, and repeat the next time your strands need a refresh. And while your in-shower routine likely always looks like this (barring the sporadic pre-wash hair mask, that is), what happens after you step out of the shower is often a completely different story. There are a number of after-wash hair products on the market, from mousse and gel to serum and leave-in conditioner, that are specifically designed to work on damp strands. Given all of these options, however, it can be challenging to know which formula is right for you. Ahead, experts explain how every leave-in product works and share which formula is best suited for your hair type.

Mousse

Mousse is one of the most common after-wash products. "Due to mousse's foamy consistency, when it is applied on the hair, it is easily dispersed from roots to ends. It saturates hair fast, whether it is wet or dry," explains Fabian Lliguin, a hairstylist and the founder of Rahua Rainforest Beauty. This product benefits fine and curly hair types most: "Mousses are great on fine hair: They add hold and definition to strands, protect and tame hair, and give unruly curls some control," shares Michelle Sultan, a celebrity hairstylist and brand ambassador for Imbue. When applied to washed hair, mousse can also banish frizz, add bounce to waves, and smooth strands while they are in protective styles, like braids.

Gel

Sabrina Rowe Holdsworth, a celebrity hairstylist and the founder of NTRL By Sabs, only recommends using gel when styling your hair in specific ways post-wash. "Gels are meant to create weight, softness, protection, and hold," she says. "If you want a really neat ponytail, bun, or updo, you want gel." This product can also come in handy if you want a "wet" look; plus, it can smooth edges and slick down curls. It's important to test different gels before committing to one, however, since different formulas often serve unique purposes: Some have softer finishes and others, like those suited for edge control, keep your hair in place for hours on end.

Hair Serum

Another product category that is commonly lumped under the after-wash umbrella? Hair serums. Sultan, however, recommends waiting until your strands are dry to apply these options. "Serums can be used to add shine after the hair is dried and styled," she explains. "Some serums are used just to add shine, while others can lock out humidity and keep frizz away."

Leave-in Conditioner

"I recommend leave-in conditioner for wavy, curly, dry, and frizzy textures, as they provide some necessary weight and extra moisture to dry, frizzy hair," Rowe Holdsworth says. These products make hair softer and easier to style—and, thanks to their creamy, nourishing ingredients, they can also provide slip during the detangling process.

Layer Your Post-Wash Products

If you have thick hair, Rowe Holdsworth recommends layering two to three after-wash products, such as a mousse followed by an oil (another post-wash option). For those with straight or curly hair that is also coarse, more products might be needed. "People who have coarse hair with medium to high density can freely layer products to find their desired results," she shares. "Complex combinations of oils, mousses, creams, sprays, and gels can be used for definition, control, and volume." Sultan says that pairing a leave-in conditioner with a lightweight liquid gel or mousse can lock in the shape of wavy hair; applying a serum last can help keep humidity at bay. Coily hair, on the other hand, can benefit from a curl-specific mousse or gel to define the wave pattern and a rich, but light oil to lock in moisture and provide extra shine.

For those with straight or curly hair that is fine, keep product application to a minimum, since any formula will add weight to strands. Rowe Holdsworth recommends using a volume-boosting spray for blow drying or diffusing hair; a light oil or curl and styling creams for frizz; and a mousse for lift and control. Sultan notes that a lightweight leave-in conditioner could work as a pre-dry treatment when applied to the ends.

The Best After-Wash Product

So, which post-wash product is ultimately best? According to our experts, the general consensus is leave-in conditioner. "After washing, apply leave-in conditioner as a base to protect your hair from environmental damage and heat styling," Lliguin says. This is also the winner because of its versatility—it's relatively easy to find a leave-in conditioner that suits your hair texture. "In most cases, I like to apply some sort of leave-in conditioner before I do anything to any hair type, as it makes the hair more pliable and allows for ease of styling," Sultan says, noting, however, that there is truly no needfor any of these products. "What I have learned in my 20 years of playing with hair and products is that when we take really good care of ourselves, we really don't need anything other than quality shampoo and conditioner. For those of us who want to control or tame our hair in some way, products like gel, mousse, and leave-in conditioners can come into play!"