How-to
सफेद बालों में मेहंदी कैसे लगाएं: समय, तरीका और सही मेहंदी
सफेद बालों पर सिर्फ मेहंदी से तांबे जैसा रंग आता है। भूरे या काले रंग के लिए मेहंदी 3–4...
Read
Yes, you can usually put pure henna on hair that has been chemically coloured, but wait 2 to 4 weeks after the last chemical dye, bleach or perm, and do a strand test first. The real risk is not henna itself but 'henna' products that contain metallic salts, which can react with chemical treatments. Pure henna with no metallic salts is the safe starting point.
Why the strand test matters
Chemically coloured, bleached or permed hair is more porous than untreated hair, so it can take henna faster and more strongly than you expect. A strand test shows you the real colour and the feel before you commit your whole head.
1
Collect a strand. Take a small lock from a hairbrush or from underneath, where it will not show.
2
Apply the paste. Mix a little henna as usual, rest it, and coat the strand.
3
Time it. Leave it for the same time you plan to use on your head, usually 1 to 3 hours.
4
Rinse and wait. Rinse with water, let it dry and judge the colour after 48 hours in daylight.
How long to wait after chemical dye, bleach or keratin
| Last treatment | Wait before henna | Notes |
|---|---|---|
| Box or salon hair dye | 2 to 4 weeks | Strand test first; henna adds warmth over the existing shade |
| Bleach or highlights | 4 weeks or more | Bleached hair is porous and takes colour fast; test carefully |
| Perm or relaxer | 4 weeks or more | Strand test for both colour and feel |
| Keratin or smoothing treatment | Ask your stylist | Henna coats the strand and can affect how a smoothing treatment behaves |
Can you use chemical dye after henna?
Pure henna and indigo do not react dangerously with chemical colour, but chemical dye may take unevenly over henna because the henna coating stays on the strand. Henna also cannot be lifted out by lightening easily. If you plan to go back to chemical colour, tell your stylist you have used henna and ask for a strand test. Products with metallic salts are the ones known to react badly with chemical treatments, which is why the label check below matters.
What colour to expect on previously dyed hair
Henna is translucent. It adds warmth over whatever colour is already there, so the result depends on your current shade. On dark dyed hair you will see a red glint; on lighter dyed hair, copper to auburn. Henna cannot lighten hair. For a darker, cooler result, follow henna with indigo using the two-step method.
Check the label before you start
- One ingredient for henna: Lawsonia inermis. Nothing else.
- No metallic salts and no PPD listed or implied.
- Avoid any 'black henna' or 'instant black' product.
- A batch number and manufacture and expiry dates.
More on this in how to read a henna label.
Always patch test too. A strand test checks colour; a patch test on the skin 48 hours before first use checks for irritation. Do both the first time.
Quick answers
Can I apply henna on coloured hair?
Yes, with pure henna, after waiting 2 to 4 weeks from the last chemical colour and doing a strand test first.
Can I apply henna after bleaching my hair?
Wait at least 4 weeks and strand test. Bleached hair is porous and can take henna strongly and quickly.
Will henna damage chemically treated hair?
Pure henna coats the hair rather than lifting the cuticle. The known risk comes from henna products with metallic salts, so check the label.
Can I dye my hair with chemical colour after henna?
Often yes, but results can be uneven because henna stays on the strand. Tell your stylist and strand test first.
Pure henna, nothing hidden
Natural Henna is 100% Lawsonia inermis from Sojat: no PPD, no metallic salts, no synthetic dyes, batch number on every pack.
Shop Natural Henna
