AIgirl has a recipe on here that a lot of us use and tweak.

I use two packets of unflavored Knox gelatin, mix in some EVCO, a little epsom, and some ACV into super heated water - maybe 1/4 cup? Mix well, the put it on your hair, put a bag over it, apply heat (either the shower water on the bag or a heating pad), rinse. Do a DT or at least a rich RO after, plenty of LI (and some light oil for me) over that.

Gelatin does AMAZING things for my hair. I don't find it drying at all, but I think some do. (and I do follow mine with rich condish).

The more I think about it, the more I think it may not be the protein you are using as much as it is the moisture you AREN'T using.
2c/3a/3b, Fine/med, Dense, high porous, & normal elas.

Lo-poo - Renpure Keratin, SMR, Giovanni SaS
clarifying - mix Johnson's H2T with low poo
Co-wash - Suave Nats. clar. or coco.
RO - GVPCB, Ion Eff. Care, TN.
LI - SMR, Cure Care, or RO
Seal - MO or Jojoba
DT - + honey, ACV, & EVOO to SM masque & GVPCB
PT - Gelatin!, CNPF
Styling - FSG, AIF, BRHG, LALS/PS, GF curl spray gel, SM Souffle/Smoothie, LOOB
Oils - MO!, EVOO, jojoba, GSO, SM Elixer, EVCO, VO5 Hairdressing