moisture vs. protein
Here is a good explanation of how to know if your hair needs moisture or protein. I copied it from NC.com’s forum, posted by redcelticcurls. (here’s the link if you want to read the entire thread)
“A good way to tell if you need protein is to do a strand test.
You take a strand of hair, wet, hold it at each end and stretch. If it snaps immediately or stretches very little, you need moisture. If it stretches 20%-30%, you probably have a good moisture/protein balance. If it stretches much more than about 30% and doesn’t shorten up again (strand stays all limp and stretched out) you may need protein. I usually do a few hairs just to get an average.
Another way is that if you see your curls getting limp and dragged out (and you can’t blame it on a low dewpoint) you may need a shot of protein.
If you are protein sensitive, your hair will feel like dead grass or straw when you use protein. In extremes, the hair can snap. It will feel dry and brittle, and adding more of a protein conditioner will just make it worse. Now, this won’t mean that you are sensitive to all proteins. Wheat is a commonly seen as an offender, but some can use it. So, you may be unable to use wheat protein, but be OK with silk or soy or keratin.
The frequency of a protein treatment all depends on your hair. I had been using one once a week, but it’s down to bi-weekly now. It all depends. That is something you’ll have to learn on your own. The strand test can be helpful in figuring this out.”