From what I've read, amla powder has about 500% more vitamin C than an orange. It's extremely acidic. If you are not careful with amla powder, you can do some serious damage to your tresses. With my first use, I used 2 T in my henna mixture and my hair was hard and matted. It tooks tons of conditioner to get my hair to untangle. The second henna was done without amla and there was a world of difference. So I decided to use it on my face because it's supposed to be an excellent face scrub. That was a disaster we won't even go into (strictly a personal reaction that hopefully most people wouldn't experience). In defense of amla, it's supposed to be a fantastic fruit with wonderful properties for the hair, but I think we should be really careful to use it properly and carefully, and when using the powder, in small amounts mixed with other ingredients. The oils are probably much easier tolerated and give better results. Shikakai powder is much gentler and conditioning to the hair, IMO. I've had great results and no problems with shikakai powder. Always remember, YMMV.