The spray has a strong smoky smell — is that normal and does it stay on the hair?

Birch tar is a traditional cosmetic ingredient obtained by dry distillation of birch bark and wood. Its distinctive smoky, almost phenolic aroma is an inherent property of the raw material, not a sign that the product has spoiled. The scent is strongest while the spray is wet on the scalp.

In practice, the intensity drops noticeably once the liquid dries — usually within 30–60 minutes. By the next morning, many users report only a faint trace, if any, especially after a night on the pillow. If you are sensitive to smells or have a social engagement soon after washing, applying in the evening gives the most time for the aroma to dissipate. Wearing a light leave-in conditioner or hair oil on the lengths (not the scalp) after the spray has dried can also help mask any residual note without interfering with the scalp contact.

Because the fragrance comes from the active ingredient itself rather than added perfume, it cannot be "washed out" separately — it fades as the tar volatilizes. If the smell is genuinely unpleasant for you or triggers headaches, this product may not be the right fit; consider a tar-free scalp tonic instead.