Formula Review

1. Is the formula okay for daily, gentle anti-dandruff use?
   The formula appears well-suited for a gentle, daily anti-dandruff shampoo.

   • The use of a Sulfate Free Shampoo Base provides a gentle cleansing action, which is good for daily use and minimizing scalp irritation.
   • The combination of Piroctone Olamine and Zinc Pyrithione at 0.5% each is effective for controlling dandruff caused by fungus. The descriptions indicate that using these two ingredients together provides maximum dandruff removal efficiency. The concentrations are within the typical recommended ranges for rinse-off products.
   • The inclusion of HyaCoat (Cationic Hyaluronic Acid) and Panthenol (Pro-Vitamin B5) helps to provide moisture and nourishment to the hair and scalp. HyaCoat can adhere to hair even after rinsing, offering long-lasting hydration, while Panthenol supports overall hair health and can help reduce irritation.
   • SugarThick acts as a thickener and can also help reduce potential irritation from the cleansing agents.
   • GuarCat Weight-less is a conditioning agent that will help make the hair soft and smooth without weighing it down, which is a good addition for a frequently used shampoo.

2. Scent without fragrance and alternative mild scents:
   The formula, as listed, does not contain added fragrance. The Mild Preserved Eco preservative is described as having no odor, so it will not contribute a scent. The other raw materials generally do not have strong pleasant odors. Therefore, the final product will likely have a very minimal, possibly slightly chemical or raw material odor.
   Given the user's allergy to all types of fragrance, it is safest to leave the formula unscented. Adding any natural essential oils or extracts, even in small amounts, carries the risk of triggering an allergic reaction. If a mild scent is strongly desired, it would require careful selection of an ingredient known for low allergenicity (which is difficult with a broad fragrance allergy) and thorough patch testing by the user. However, the safest approach for a fragrance allergy is to omit scent entirely.

3. Sufficiency of the preservative:
   The formula uses 1% Mild Preserved Eco. The product description for Mild Preserved Eco recommends a usage rate of 1.0-1.5% for general cosmetic formulas and 1.5-2.0% for products that are difficult to control infection. Shampoo, being a water-based product used in a humid environment, can be susceptible to microbial growth. While 1% is within the suggested range, it is at the lower end.
   To ensure adequate preservation for this specific formula and its intended use (daily, in a shower environment), it is highly recommended to perform a challenge test. This test will confirm if the 1% concentration is sufficient to protect the product from microbial contamination throughout its intended shelf life under typical usage conditions. If the challenge test fails, increasing the concentration of Mild Preserved Eco (up to 2%) or considering an alternative or additional preservative may be necessary.

In summary, the formula is a good base for a gentle anti-dandruff shampoo. It is best left unscented due to the allergy. A challenge test is crucial to confirm the preservative system's effectiveness.