Simply put, a heat protectant shields “your hair from heat, which may burn your hair, cause split ends, make your hair dry and lifeless,” says Iudina. Additionally, she adds, it can help your color-treated hair last longer. Without this safety net, hot tools strip your hair of its natural protein, making it weaker over time, disrupting natural curl patterns, and causing increased breakage.

What We Love: A trio of emollient-rich oils drenched our hair in moisture, effectively smoothing hair and taming flyaways after one use. It’s a fine line for us curlies to walk: We need all the hydration help we can get, but without causing our spirals to become heavy and fall flat. Yet, this Mizani spray protectant shows that small and simple can most certainly be mighty. With a lightweight mix of conditioning ingredients, such as tea tree oil and propylene glycol, we got better-defined bouncier coils, ringlets, and waves.

We’ve turned dpHue before when we wanted to keep our blonde hues bright and strands glossy in-between visits. Similar to those two color-centric formulas, this protective spray is free of gloss-stripping additives, like sulfates. Instead, the base of the formula is tocopherol, also known as vitamin E, to gently hydrate our hair and supply it with the nutrients it needs to be strong and healthy. And, in turn, our color-treated hair lasts longer and looks richer.

Heat tools for hair — like straighteners, curling irons and hair dryers — are one of the biggest culprits of hair damage. Although there is no way to totally reverse the damage, you can minimize some negative effects by applying a thermal protecting leave-in styling product. In fact, two studies published in the Journal of Cosmetic Science ( 1998 and 2011) have shown that several ingredients (which include copolymers, hydrolyzed protein and cationic surfactants) can minimize hair breakage when applied before thermal exposure. We love that although it’s not a fully liquid texture—think of it more like a light, milky serum—it comes in a spray bottle that makes it easy to distribute. It’s not heavy or greasy in the hair, and it works to smooth, soften, and significantly reduce frizz. We wish it was a bit more moisturizing, especially for dead ends, but considering how lightweight it is, how well it guardsgaurds against heat damage and frizz, and the fact that it provides UV protection, we still strongly recommend it. What We Love: Our hair drank up all the softening and shine-imparting benefits in this lightweight, spray formula, which was so nourishing, we’d guess it was a leave-in conditioner. Huang ZR, Lin YK, Fang JY. Biological and pharmacological activities of squalene and related compounds: potential uses in cosmetic dermatology. Molecules. 2009;14(1):540-554. Published 2009 Jan 23. doi:10.3390/molecules14010540Yes, just take it from the pros: “Hair should never be exposed to heat without this barrier,” says Johnson. She adds that heat protectants function like a barrier between your hair and the high temperatures from hot tools. To form this barrier, formulas usually feature ingredients like coconut oil, amino acids, and proteins that shield the hair cuticle from damage. Additionally, many formulas include hydrating emollients like squalane and glycerin to combat any dryness caused by heat.