Which of the following is the pH range for most conditioners?

• A. 7.5 - 9.0
• B. 6.0 - 7.0
• C. 2.0 - 3.0
• D. 3.5 - 5.5

Answer: (D)

Conditioners are meant to smooth the hair and help close the cuticle so moisture stays in and tangling is reduced. To achieve that, they’re formulated in a mildly acidic pH range, which helps the cuticle lie flat and reflects light for smoother, shinier hair. The pH range that fits this purpose is 3.5 to 5.5.

If the product were too basic, like the higher end of the scale, the cuticle would lift and hair could feel rough or frizzy, and it might not hold moisture as well. A near-neutral range (around 6.0–7.0) is not as effective at sealing the cuticle, so moisture retention isn’t as good. An overly acidic range (2.0–3.0) can be irritating to the scalp and could be damaging to hair over time.

So, the best fit for most conditioners is 3.5 to 5.5.