The culprit: Clairol Natural Instincts (semi-permanent dye); the newer version/formula which contains the 2 week color refresher packet.
The situation: My hair had been responding well to the older formula, or so it seemed. I noticed a subtle change in texture two months ago after the first treatment with the new formula. I chalked it up to a need for a clarifying shampoo. Then just a couple weeks ago, I repeated the treatment and right after was when my hair went haywire, with a drastically weakened curl pattern, flatness and fuzziness, and took forever drying.
Here's what I know now: it likely was more than the open cuticles/high porosity caused by the dye. Ten of these CNI colors have been officially recalled because they weren't formulated correctly. I have used at least one (#23R). Possibly more, because they are now expanding the original recall:
P&G expands Clairol Natural Instincts recall | Drug Store News
Here are disgruntled reviewers (2.3 stars out of 90 reviews)
Clairol Natural Instincts Review | WARNING!!! DO NOT USE!!!
A related amazon review search shows an alarming number of customers have had their hair trashed from this new formula. The two most common complaints were:
1. Hair turned orange (or some clownish, bright color).
2. Dye didn't take at all.
(Another common complaint was "turned my hair to straw".)
I suspect they made two errors: sent out some products with too much peroxide, and sent out others without enough. I likely got a peroxide overdose, based on my hair "symptoms". I'll keep using protein treatments, without going overboard, and then condition afterward.
I will stay the **** away from Natural Instincts. I actually still trust Clairol overall. I was going to use a henna/indigo/amla treatment, but instead I think I'm going to give my hair a rest, then use Clairol Professionals for gray hair, which has 0 peroxide in it.