Taking on a few more questions from you and there is a lot of buzzing about protein treatments and what they can do for hair.
To summarise it, protein treatments are known to temporarily repair and strengthen hair. They do this by filling up gaps in the cuticle and if of a sufficiently small size can also penetrate to the cortex.(Journal of Cosmetic Science, pg69-87, 1993).
For natural hair damage tends to come from normal weathering - washing, drying, combing, heat use etc. Colour treated natural hair and relaxed hair can suffer from more cuticle damage.
1. Is a plant based protein source lighter than an animal based source?
No. It is more important to assess how the conditioner makes your hair feel. Many bloggers, vloggers etc warn people on how to spot protein but forget to mention that you should really look for where it is on the list. If if is after the first five ingredients there is probably not much in the bottle.
Additionally there are no products that tell you how hydrolysed the protein is (read this post to find out why protein has to be broken up - or hydrolysed to be useful). In short , pun intended, if the protein is not of the right small size (and it does vary according to protein) it may not give your hair the desired effect.
Therefore, comparing Aphogee with its keratin protein in the first 5 ingredients to Giovanni with its soy protein listed as the 17th ingredient is just unrealistic. Use the product and if you don't like it either on its own or in combination (For example a follow up conditioner or leave in or oil) then just try something else.
2. Does coconut oil contain protein
No it does not. I repeat, no coconut oil does not contain protein. Oils are pressed out of seeds, in the case of coconut oil, heating up the flesh and straining it out. The oil is very easily separated from the flesh once heated using a sieve.
The straw like feel some people find with coconut oil is usually related to using too much product because coconut oil is not as viscous as other oils . Hardening of the hair is related usually to temperature because coconut oil solidifies at a fairly low temperature so a cold winter breeze can stiffen hair very fast.
Some people (like me) love coconut oil, other people just do not. It is a bit like marmite, if you find that even using less does not help ( see the fingertip tip ), just leave it!
3. Does coconut milk contain protein?
Yes coconut milk does contain protein. Coconut milk is made from suspending the flesh in water and may contain bits of the flesh. However this protein is usually not hydrolysed (yep hydrolysed again). Pretty much like eggs, it is unlikely to be as effective as a hydrolysed protein.
It is the marmite story for coconut milk - if you like its effect use it, if you don't just leave it!
4. Do protein treatments stop hair shedding?
No, there is a difference between hair shedding (i.e hair with a bulb coming out of the follicle) and breakage (i.e hair breaking off due to handling). At times you can confuse the two but looking for a bulb is always the way to tell the difference. Hair shedding is a programmed event it is not changed by protein treatments. Breakage on the other hand can be stopped temporarily.
5. Does natural hair require protein treatment?
There is no harm in trying it out if you want to. The worst thing that can happen is that you hate it and have to wash your hair all over again.
If you use heat frequently, regularly wear your hair in styles that require combing or colour treat your hair, a protein treatment may be quite useful.