Henna is one of the most popular beauty herbs used in India. It is more commonly known as mehndi in our country. People use it as a decorative tattoo as well as for colouring gray hair.
Henna is a herb, so it is considered safe to colour gray hair as compared to synthetic dyes. It is very commonly used as an alternative to synthetic hair dyes. In this post, we would discuss uses, benefits and disadvantages of henna as a hair colouring agent.
In commonly spoken language, people use the words 'hair dye' & 'hair color' interchangeably. But, are hair colors and dyes the same? Are dyes stronger than colors? Do they work differently? If you wish to know the difference, do read our article: What’s the difference between hair color & hair dye?
From where is henna obtained ?
Henna is obtained from the dried leaves and stem of Lawsonia intermis which grows in India, Egypt and Tunisia.
Is henna a hair dye?
Yes. In fact, henna is the only available natural hair dye.
Henna is a semi permanent type of hair dye. Semi permanent dyes contain neither ammonia nor hydrogen peroxide. The color molecules of semi permanent dyes do not penetrate into the cortex of the hair. They just get deposited on and in the cuticle (outermost layer of the hair).
To know more about semi-permanent hair dyes, read our article: The different types of hair dyes
How does henna act as dye?
The active ingredient is lawsone (2-hydroxy 1,4 napthaquinone). The active ingredient is obtained by treating the leaves with sodium bicarbonate. Henna is usually available in market as a powder that is mixed with plain water or black tea water to make a paste. It is allowed to stand for 4-6 hours, and then applied over hair for 2-4 hours, followed by washing and shampooing. When applied to the hair, the lawsone molecules reach to the cuticles of the hair shaft and bind with the keratin. Henna imparts a orange red tint to hair, which gradually fades with 10-12 shampoo washings.
What are the additives in herbal henna preparations available in market?
Henna preparations in Indian markets have many herbs or ingredients added to improve quality and colour of hair.
- Shikakai and reetha act as natural cleansing agents
- Coffee powder, black tea, kattha, Manjistha deepen the henna colour to dark brown
- Aamla is said to stimulate growth and strengthen hair follicles and prevents dandruff
- Bhingraj is said to prevent premature greying of hair and hair loss.
- Indigo is another herbal dye. It is added to henna to provide superior colour results. It increases the depth of colour to dark brown.
- Hibiscus adds shine to the hair and is said to prevent dandruff.
- Some preparations are available as black henna or Kali mehndi contain para dyes in addition to henna. Such preparations can cause reactions in allergic individuals.
What are the advantages of henna over permanent dyes?
- Henna is considered safe, if present in 100% pure form. It can be used safely by people having allergy to PPD (p-phenylenediamine) containing dyes.
To know more about PPD & the various types of hair dyes, read our article: The different types of hair dyes
- Henna is gentler on your hair than permanent hair color because it only deposits dye on to the surface, not inside the cortex. Unlike permanent dyes, henna doesn't harm cuticle of hair shaft. It rather strengthens hair shaft and repairs split ends.
- Henna is a great conditioner for your hair. It adds shine and volume to it, and also shields it from further damage by forming a coating on it. It protects the hair from sun damage. Regular use of henna can loosen the curl pattern of hair, making them more manageable and less frizzy.
- It promotes hair growth, reduces hair fall, dandruff and other scalp problems.
What are the disadvantages of using henna?
- Some people show allergy to henna which is mainly attributed to additives in henna mixture such as diaminotolulene and diaminobenzenes. Though allergic reactions are less common and less severe as compared to the reaction with permanent dyes containing PPD.
- Some low quality henna dyes or black mehndi may contain additives like PPD and metallic salts to make the dye stain stronger and darker. The people allergic to para dyes shouldn't use such preparations.
- Colour results by henna are inferior to permanent dyes. As henna is a depositing dye, so it cannot lighten your original hair shade. Henna only provide single shade of colour. Pure henna powder imparts a red to orange-red colour. Mixing with other herbs as indigo or cocoa, one can get brownish shade.
- In some individuals, henna has a drying effect on scalp. In such case, one can add a tablespoon of curd or olive oil to the henna paste, then apply on hair.
- Henna application is little messy and time consuming.
Henna (mehndi) is a very safe way to colour your hair. It not only covers grey hair but also makes hair stronger, voluminous and shiny. However, henna use is messy and time consuming and results are inferior to para dyes.
We hope after reading all benefits and disadvantages of henna, you can come to a decision whether to choose henna or synthetic dye to colour your hair. If you like this post, please don't forget to share it with your friends.
Dr Monika Misra
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