Traditionally, people wash their hair by applying shampoo first, followed by conditioner. However, a recent online article titled "The Order of Washing Your Hair Has Always Been Wrong" challenges conventional wisdom. This claim originated from a foreign netizen's personal experiment, where she discovered that using conditioner before shampoo resulted in hair that felt more voluminous and natural after washing.Is this claim scientifically sound, and does it apply to everyone?
In reality, applying conditioner before shampoo is unscientific—both in terms of product composition and care efficacy. This is because hair is covered by a dense layer of cuticles. These cuticles close in acidic conditions and open in alkaline conditions. When closed, hair appears smooth and silky.Both shampoo and conditioner leverage this principle. Alkaline shampoo opens the cuticles to cleanse the hair, but the proteins within hair are most vulnerable to damage in an alkaline environment. Therefore, an acidic conditioner is applied afterward to neutralize the pH, close the cuticles, and restore smoothness.
The "volumizing" effect often touted online from reversing the order is actually an illusion. Conditioning before shampooing causes the hair's cuticle keratin to swell with water absorption. Combined with the removal of natural oils, increased friction from rubbing creates the illusion of volume, but the conditioning effect is significantly reduced.
For optimal hair care, start by selecting the right shampoo. Since the scalp is mildly acidic, those with dry hair should choose shampoos with a pH below 7. Individuals with severely damaged or extremely dry hair may experience tangling during washing. Applying conditioner first can prevent knots, but for true conditioning benefits, repeat the conditioner application after shampooing.Additionally, pouring shampoo directly onto the scalp and rubbing it in can damage hair. Instead, lather the shampoo in your hands first, then gently massage the scalp with fingertips. For the ends, use your fingers to gently squeeze and rub. Rinse thoroughly with lukewarm water after completing the entire process.
Whether hair appears voluminous after washing largely depends on conditioner application technique. Conditioner should only be applied from mid-lengths to ends—never on the scalp. Otherwise, hair will lie flat against the scalp, losing volume. Proper blow-drying also enhances volume: blow-dry roots against the natural hair growth direction, or lift sections of hair and blow-dry strand by strand.