Treatment should be adapted to each type of dandruff and should be started with a suitable shampoo.
At first, it is best to use anti dandruff shampoo at pH 5 containing an anti-fungal, an anti-septic a mild detergent and regenerative properties (lanolin or camphor).
For oily dandruff an absorbent clay mask is recommended.
Essential oils have amazing therapeutic virtues. Among these extracts of medicinal plant, the most effective against dandruff are made of Mint, Eucalyptus, Juniper, Thyme, Tea Tree...
You can try homemade remedies like massage with sea salt or coconut oil, a rinse with apple cider vinegar or lemon juice, a bath of olive oil or aspirin dissolved in water.
For each antidote, rinse with clear water and fallow with a regular shampoo.
Please note that these tips are not cosmetic products and can contribute to dry your skin and hair. Stay aware of the use and the frequency of applications.
In case of severe dandruff, it is best to consult a dermatologist. There could be a risk of inflammation of the scalp (especially if there is itching) or any appearance of eczema or psoriasis.