I've been using henna for almost a year and it's never loosened my coils. I henna my hair in twists though.

I've also never noticed that Alma's tightened my coils.
Black African Hair
There's only one like it in the world!

Preshampoo - Joico Moisture Recovery Treatment Balm
Shampoo - KC Come Clean
Condition - Joico Moisture Recovery
Leave In - KCKT, Kiehl's Formula 133
Seal - Jojoba Oil
Moisturize - Rosewater