It started when I was trying to improve the solid shampoo for oily hair with a plant extract (indigo).

But, according to the 15 people tested, the product's performance was not improved, and 3 people felt they had less itchy scalp.

After several attempts, I finally improved the solid shampoo for oily hair with the desired result (with another extract: shikakai).

An unexpected request

I received a call from one of the 3 people who had improvement in their itchy scalp asking if I had any product samples left as she explained that the product reduced her itching tremendously after using it for over a month.

I wondered if this was really happening because of the product and if it wasn't just a placebo effect.

This time I recruited 6 people who had itchy scalps.

Failure

After 3 weeks of testing the product, all 6 people reported no improvement in itching.

Even the first 3 people who had already seen an improvement were now saying the product was not working.

So before I came to the conclusion, I called all 3 people to explain that it was just a placebo effect and that the product had nothing to do with their improvement.

But one person told me, " I liked the blue shampoo ."

Following telephone conversations, I learned that these 3 people who experienced a reduction in itching, initially received the blue version of the indigo extract in the shampoo.

Blue on trial

So this time, the blue ones are tested on the same group of 6 people with 1 additional person.

This additional person is a client of Melo Ayurveda, who was looking for a solution for her seborrheic dermatitis.

Results

This time all 6 people said there was a reduction in itching and the 7th person also said there was great relief for his sensitive scalp.

Conclusion

Indigo extract comes in two colors: green and blue. The blue color comes from the leaves undergoing a fermentation process.

The plant creates a molecule called indirubin which has anti-inflammatory properties and there are also clinical trials demonstrating the antipsoriatic potential of indirubin. ( Lin et al., 2018; Gaitanis et al., 2018).

But this evidence only shows that the effect is produced with a leave-in product, not in a rinse-off product.

It is not certain that indirubin alone produces these multiple effects, but it is important to mention that the product tested also contained pongamol (derived from Pongamia glabra ), another powerful molecule that downregulates stress proteins in the skin.

In conclusion, the product showed a significant improvement. Ayurvedic plants possess a broad spectrum of interesting molecules that are still little used in cosmetics.