Understanding Henna

Understanding Henna: What You’re Really Putting in Your Hair

Henna is a natural dye derived from the Lawsonia inermis plant. When it's pure and unadulterated, it imparts a warm reddish-orange hue to the hair. It’s a popular choice for those seeking a more holistic or chemical-free coloring option, and it's often praised for its conditioning properties.

However, not all henna is created equal. Many commercial henna products—often referred to as "compound henna"—contain metallic salts, indigo, or other chemical additives to enhance or alter the final color. These additives can have a dramatic impact on how your hair responds to permanent color later.

What Happens When You Apply Permanent Color Over Henna?

Here’s the professional truth: hair that has been treated with henna (especially compound henna) is unpredictable when exposed to traditional permanent hair dye. Here’s what can happen:

1. Uneven Color Absorption

Henna coats the hair shaft and creates a barrier. When you try to apply permanent color on top, the dye molecules often can't fully penetrate. This results in patchy, uneven color that doesn't resemble what’s shown on the box or even what you'd expect from salon-grade products.

2. Unexpected Color Results

Even if the hair takes some of the dye, the underlying henna color will affect the final shade. For example, applying an ash brown over henna-treated hair can result in a muddy green or orange tint because of the interaction between the base pigments.

3. Chemical Reactions

This is particularly dangerous with compound henna. Metallic salts can react with the ammonia and peroxide in permanent dyes, leading to hair that heats up, smokes, or even becomes brittle and BREAKS OFF. In some cases, it can damage the hair irreparably.

The Waiting Game: Timing Matters

If you’ve used henna and want to switch to permanent hair dye, timing and preparation are everything. Here's what I recommend as a stylist:

• Wait at least 6 to 12 months after using henna before applying permanent color—especially if you're unsure whether the henna used was pure.
• Clarify your hair regularly to help strip away residual henna buildup.
• Do a strand test. Always. Before applying color all over, test a small section of hair to see how it reacts.

Final Thoughts

Henna is a beautiful, natural dye—but it doesn’t play well with others. If you’re thinking about switching from henna to permanent hair color, your best bet is to consult a professional who understands the science and artistry of color correction. With the right care and patience, it is possible to make the transition—safely and beautifully.

Have questions about your specific hair history? Book a consultation with a trusted stylist and bring a list of all products you've used. It could make all the difference between a hair disaster and a hair transformation.