For those who don't know, terminal length is basically a term describing how long your hair is genetically programmed to grow. The debate in the hair community is whether or not terminal length really exists. It interests me particularly because...well, I don't wanna be aiming for TBL and then find out my hair ain't gonna grow any longer than eyebrow length.
So here's what I've dug up on the subject:
Hair growth is divided into three different phases--the anagen (growing), catagen (transition), and telogen (resting) phases. The telogen phase is when the hair has stopped growing and sheds from the scalp, so of course, this is the stage in which the hair will reach its terminal length.
Supposedly, it can take your hair anywhere from 3 - 7 years to reach its terminal length, at which time you're stuck with whatever length your hair has achieved. So does that mean that you can grow your hair for 7 years and still only end up with SL tresses?
While it may be true that your hair is genetically programmed (the jury is still out on this one), it may be a better description to say that your hair has a terminal time rather than a terminal length. Why? Because although your hair may only grow for 7 years, in those 7 years, many different things can affect how quickly or how slowly your hair grows and thus, how much length you get or even how long your hair appears to be.
Keisha and Tanya each have a growth (anagen) phase that lasts 5 years. That is to say, their terminal times are both 5 years. However, Keisha's hair grows 6 inches a year while Tanya's hair only grows 3 inches a year. In 5 years, Keisha's hair will have grown 30 inches while Tanya's hair will have only grown 15. Same terminal time, different ending lengths.
Janay and Kendra each have a growth (anagen) phase that lasts 4 years. That is to say, their terminal times are both 4 years. They also have the same growth rate of 6 inches a year. However, Janay is 4'5 while Kendra is 6'5. In 4 years, although both have grown 24 inches of hair, Janay's hair will be classic length (CL; halfway down the body) while Kendra's hair will only be MBL. Same terminal time and lengths, different ending appearances.
How do you know you've reached terminal time?
Assuming that this phenomenon does truly exist, ladies who have claimed to have reached this point in their hair growth journeys have cited any combination of a severe tapering of their ends, hair that will grow thicker as shorter hairs catch up, but not longer, and just a plain absence of growth.
What can you do to maximize the growth you get in your terminal time?
Of course, the answer to this question will be different for every head of hair. There is no one way to maximize your growth potential. Some women see great success with growth aids like MegaTek, Mail-N-Tail Grow, Wild Growth Oil, or miconazole (yes, yeast infection cream), while some will not. Others will benefit from frequent cowashing, scalp massages, increasing deep conitioning, or any mixture of things. And still others prefer to take supplements for hair growth including biotin and prenatal pills. How you maximize your growth will depend on you and your specific head of hair.
But we all know the basics: keep your scalp clean, keep your hair conditioned, moisturized, sealed, and protected and you'll see growth regardless of whether you use a growth aid or not. :)