Ammonia: it opens the hair cuticles, making it more fragile.
Hydrogen peroxide: It atta.cks the hair follicle and can irritate the skin.
Paraphenylenediamine (PPD): Known to lead to severe allergic reactions in some people.
These chemical compounds can not only destr0y hair fibers, but also cause scalp irritation . So, how can you safely darken your hair?
The natural recipe for darkening your hair

Fortunately, there’s a natural and effective way to darken gray hair without using chemicals. Here’s a simple method you can do at home.

The ingredients:
2 tablespoons of pure honey (gently opens hair cuticles)
2 tablespoons of ground coffee or concentrated black tea (natural pigments)
1 tablespoon of apple cider vinegar (fixes color and balances pH)
1 tablespoon of baby oil (nourishes and protects hair)
Preparation:
Blend all the ingredients until you get a smooth paste.
Apply to clean, slightly damp hair, concentrating on the areas to be darkened.
Leave on for 1 to 2 hours. The longer the exposure time, the more pronounced the effect will be.
Soak thoroughly with cold water.
Repeat twice a week for optimal results.
The benefits of this natural method

Unlike chemical dyes, this recipe allows you to darken your hair gently, without damaging it.

Maintain the hair fiber: no corrosive substances.
Nourishes hair: thanks to honey and baby oil.
Progressive effect: the color becomes more intense over time.
Suitable for eyebrows: no irritation on sensitive skin.
For whom?
Dark hair: Coffee and black tea work best.
Blonde or very gray hair: several applications may be necessary for optimal results.
Dry hair: Baby oil provides valuable hydration.
Tips for better results
To achieve the effectiveness of this natural coloring, also adopt good eating habits:

Consume nuts, spinach and avocado, which are high in copper and antioxidants.
Avoid using very hot shampoos which can dull the color.
Massage your scalp regularly to activate blood circulation.