Permanent 40 Vol Coloring Creme Developer - 16 oz

Kenra Permanent 40 Vol is a maximum strength developer designed for the most stubborn, resistant hair and the darkest base colors. The 40 volume concentration provides faster processing times and greater lifting power compared to 10, 20, or 30 vol developers. It's ideal for achieving significant color changes, covering gray hair, or lightening darker shades. For finer or previously colored hair, lower volumes may be more appropriate to minimize damage.

Kenra Permanent 40 Vol is a professional-strength developer and may be too intense for very sensitive or compromised scalps. Always perform a patch test 24-48 hours before application. If you have a history of scalp sensitivity, irritation, or allergies to hair color products, consult with a professional colorist who can assess your scalp condition and recommend an appropriate volume or alternative solution.

Using 40 Vol on previously colored or chemically treated hair carries a higher risk of damage, breakage, and over-processing. For pre-colored hair, professionals typically recommend lower volumes (10-20 Vol) depending on the hair's condition and porosity. A strand test is essential to ensure the hair can tolerate the developer without compromising integrity. Consult a professional colorist if your hair has been recently treated.