It may seem impossible to even think about it but we can overdo just about anything. Conditioning our hair is a 'must' for naturals and most of us use way more conditioner than cleanser. From regular conditioner to deep conditioners we make sure to keep them on hand and to use them heavily.
We all know the benefits of a deep conditioning ESPECIALLY if one is applying heat, color or just living in this world with all its pollutants. But is there a such thing as over doing it? The answer to this is a resounding "YES!"
Can you over-condition your hair?
I used to regard this as a nonsense term but when I did some research, I do now know that it is possible. A study done on nails (same keratin protein as hair) was performed to find out why nails get weaker with repeated water exposure. The study found that exposing nails to water for over 15 minutes (remembering that at 15 minutes the protein is saturated) led to the keratin coiling different from normal and this was linked to softening and weakness (BBA,pp 210-216,1999).
There are many naturals who will condition their hair for hours at a time because they like the softness that it develops. If you are in this group, you are someone who likes over-conditioned hair. The softness you are feeling is most likely related to the change in the keratin and you should be careful when handling your hair when it is that soft as it will be weaker until it has time to recover its stronger conformation. The Natural Haven
Basically, you will have complete absorption and benefits of a conditioner within 20 to 30 minutes and if you use heat it shouldn't be above 95°F. I am a heavy handed, over-conditioning Natural and will be pulling back from the overnight conditioning. With the lack of color and heat I apply to my hair I really don't need the conditioner on more than a few minutes. No wonder my hair won't do a damn thing the first couple of days after I wash it!
This is called hygral fatigue. This is what happens when the cuticle swells and contracts excessively, which is caused by the constant reapplication of water to the hair after it has dried. Since the cuticle is not designed to open and close this frequently, it causes the strand to weaken and eventually break. Some practices that may cause over-hydration are the maximum hydration method (MHM), overnight conditioning, re-wetting the hair each day, not using products that contain protein, etc.
Give hair a water break sometimes and realize a protein treatment is in order. Over-conditioning hair or hygral fatigue are one in the same so make sure to offset moisture with protein when you feel you may be fall prey to this problem.