The gelatin in IAGirl's PT is collagen protein, but I'm not sure exactly where that ranks as far as protein strength goes. My hair absolutely loved it though.
CG since 11/2011
2c /3a F /Mii, low porosity

Summer Products /Routine:
Clarifying: ACV rinses, Suave Professional Men Deep Clean Peppermint
Low Poo: Renpure Luxurious Argan Oil
Co-washes: VO5 Kiwi Lime Squeeze or Strawberries & Cream
RO: VO5 KLS or S&C, Cure Care
LI (if needed): VO5 S&C, VO5 SC, Cure Care
Stylers: FSG, AIF,
Tresemme Flawless Curls Bouncy Curls gel
PT: IAGirl's (link) as needed