I've been meaning to come in here and post about this. I just used yogurt in my henna for the first time, and it was my
BEST henna ever, by far.
I use Lush Caca Rouge as my henna. This time, I added some full-fat plain Greek yogurt, and I also used nettle tea in place of water for the very first time. I left my mixture in for 3 hours, and used my heat cap for one of those hours.
The yogurt made an
incredible difference! My hair felt SO soft, smooth, moisturized, and strong when I rinsed it out, and in the days to follow. Henna usually dries out my hair, and I have to wait about 7-10 days for my hair to return to normal before I BKT...but this time, I really didn't have to wait at all. My hairdresser noticed the difference in my hair immediately, and commented on how soft it was, and how easy it was to comb through.
I always do a good moisture DC before and after I henna, and I actually added yogurt and buttermilk to my DCs this time as well. I have no words for how AWESOME yogurt is for type 4 hair.
It eliminates tangles and knots, moisturizes brilliantly, stretches the curl pattern to make my hair easier to work with, and gives me a soft and smooth feeling.
I feel that yogurt increases the moisturizing aspect of my DC and my henna, by about 50%. I have continued to use yogurt and/or buttermilk in my conditioners, and the results have been fantastic. I highly recommend it.
ETA: I experienced NO protein overload. For some reason, the lactic acid in the yogurt and buttermilk is highly moisturizing to my hair, even though both of those foods are high in protein. The yogurt actually negated the overly drying, protein-like effects of the henna, but my hair still received all of henna's strengthening benefits.
I also noticed that lactic acid is an ingredient in most formulas of Roux Fermodyl leave-in, which is a staple of mine. I now suspect that the lactic acid provides much of Fermodyl's conditioning benefits, and yogurt appears to be cheaper, more convenient, and more effective than Fermodyl.