The mechanism of action of anti-hair loss shampoos is usually shaped by the effect of several different active ingredients on the hair follicles. These shampoos are formulated to address various causes of hair loss. Here are the main mechanisms of action of anti-hair loss shampoos:
 1. **DHT (Dihydrotestosterone) Reduction
 One of the most common causes of hair loss is the conversion of testosterone into DHT in the body. DHT shrinks hair follicles and shortens the hair growth cycle, leading to hair loss. Some hair loss prevention shampoos contain ingredients that help block DHT from affecting the hair follicles. For example:
 Saw palmetto: This herbal extract may reduce hair loss by inhibiting DHT production.
 2. **Nourishing and Strengthening Hair Roots**
 Shampoos that can be effective against hair loss contain ingredients that strengthen hair roots and promote healthy hair growth. These ingredients support the hair growth phase by increasing blood circulation. Prominent ingredients may include:
 - **Biotin (vitamin B7)**: Promotes hair growth and helps strengthen the roots.
 - **Caffeine**: Increases blood flow to the hair roots, allowing more nutrients to reach the hair follicles.
 - **Zinc**: It is an important mineral for hair health, its deficiency can lead to hair loss.
 3. **Stimulating Hair Follicles**
 Some shampoos work to speed up the hair growth cycle by stimulating the hair follicles. These shampoos usually:
 - **Aminexil**: It is an active ingredient used to prevent hair loss. It strengthens hair roots and helps prevent hair loss.
 4. **Protection of Hair Against External Factors**
 Environmental factors (such as air pollution, UV rays, stress, etc.) can cause hair loss. Anti-hair loss shampoos may contain ingredients that help protect the hair against these factors. For example:
 - **Antioxidants**: Substances that help protect hair from free radicals. For example, vitamin E can help strengthen hair and prevent hair loss.
 - **Phytoextracts and herbal extracts**: Ingredients such as aloe vera and green tea extract nourish the hair and protect it against environmental factors.
 5. **Providing Oil Balance**
 Excessive oil production can cause blockages at the roots of the hair, leading to hair loss. Anti-hair loss shampoos may contain ingredients that help balance sebum (oil) production. For example:
 - **Tea tree oil**: It has antimicrobial properties and can help prevent blockages in hair follicles.
 - **Salicylic acid**: Cleanses the scalp, opens clogged pores and promotes hair growth.
 6. **Regulating Hair Period**
 Hair growth occurs in three phases: anagen (growth phase), catagen (transition phase), and telogen (resting phase). Anti-hair loss shampoos can help keep more hair in the active growth phase by making the anagen phase last longer.
 In conclusion
 Anti-hair loss shampoos combat various causes of hair loss with different mechanisms of action. These shampoos generally strengthen and nourish the hair roots, reduce the effects of DHT and protect against environmental factors. However, if hair loss is due to genetic, hormonal or health-related problems, shampoos can only play a supporting role. For a long-term solution, it is best to seek help from a dermatologist or specialist doctor.