JessiiLeighh hit on several good points, but I need to point out that the foods she listed for protein treatments (eggs, yogurt, etc.) will not do anything in terms of getting protein into your hair--the protein molecules are too large. If you want a homemade protein treatment, your best bet is unflavored gelatin. However, with meduim/coarse hair, you should probably start with some more gentle commercial products to avoid any adverse responses to excessive protein. Keratin and silk amino acids are generally better tolerated proteins for people with otherwise protein sensitive hair. It might be that your porosity is high enough that you can handle heavy hits of protein, but I would suggest starting slowly just in case.

3a/f/iii
Modified CG since 11/5/11
CLEANSE: CJ Daily Fix, DevaCare No-Poo, CHS Treatment Shampoo
RO: SS Caitlin's Conditioner, CJ Beauticurls Strengthening
LI: SS Repairing Protein Treatment, CHS Silk Leave-In
STYLE: Re:Coil, Curl Keeper, Deva Ultra Defining Gel, Curls Rock Amplifier,Sweet Curls Elixirs Okra Gel and Hard Hold Gel, SS Curl Enhancing Jelly and Firm Hold Gel