Anti-dandruff shampoos contain a variety of ingredients aimed at addressing the root causes of dandruff and relieving symptoms such as flaking and itching. Here are some common active ingredients found in these shampoos, along with their functions:

1. Zinc Pyrithione: An antifungal and antibacterial agent that effectively controls dandruff caused by the overgrowth of Malassezia fungi.
2. Ketoconazole: A broad-spectrum antifungal ingredient that targets a wide range of fungi, including those responsible for dandruff and seborrheic dermatitis.
3. Selenium Sulfide: This ingredient slows down the growth and shedding of skin cells, reducing flakiness, and also has antifungal properties.
4. Salicylic Acid: Helps to exfoliate the scalp, removing dead skin cells and loosening flakes. It can be particularly useful for those with thick scales.
5. Coal Tar: Slows down cell growth and reduces inflammation, thereby decreasing flaking and itching. It also has antifungal properties.
6. Octopirox (Piroctone Olamine): An antifungal agent that helps control the growth of dandruff-causing fungi.
7. Ciclopirox: Another antifungal ingredient that combats fungal infections on the scalp.

In addition to these active ingredients, anti-dandruff shampoos also contain standard shampoo components such as:

• Surfactants: These are cleansing agents that help to remove dirt, oil, and product buildup from the hair and scalp.
• Conditioners: Ingredients like silicones, panthenol, or hydrolyzed proteins to improve hair manageability and reduce dryness.
• pH Adjusters: To ensure the shampoo's pH is compatible with the natural pH of the scalp, typically between 4.5 and 5.5.
• Preservatives: To prevent bacterial and fungal growth in the product itself.
• Fragrances: Many shampoos include fragrances to mask any unpleasant odors from the active ingredients and to provide a pleasant scent.

It's important to choose an anti-dandruff shampoo based on the specific needs of your scalp and hair, and to follow the usage instructions carefully. If one ingredient doesn't seem to be effective, switching to a shampoo with a different active ingredient may yield better results.