When, where, and how your hair grows can seem like a huge mystery. Especially since there are so many factors that can affect it. For example, one of our customers, let’s call her Cassie, loooooooved her hair while pregnant. Her bundle of joy arrived and then a few months later, her hair started shedding. A lot of it. Like, tons. Cassie was freaking out. Raise your hand if you’ve been there!
Here we are going to describe the basic hair growth stages: anagen, catagen, and telogen. Understanding these phases will help new-mama Cassie breathe easier and sleep a little better. Okay, maybe not sleep better.
The first stage is the longest of the growth cycle. It can last anywhere from a few months up to 8 years for a single hair! On average, the anagen phase will be at its longest length in your late teens to mid-twenties. The anagen phase length is coded into our genes and regulated by hormones known as androgens, which can either promote or prevent hair growth. And which are currently being researched for their precise effects.
In the first zone of the follicle, the cells in the root of the hair divide and replicate. (Think back to high school biology) Nutrients and hair pigment are added through the dermal papilla to the bulb and help fuel this activity. As the cells divide, they move up the follicle, moving into the keratinization zone. (Area where your hair ‘exfoliates’ and forms keratin)
This is when cystine links are formed, and the tough keratin scales are formed. The keratin is beginning to stabilize but is not fully hardened. They proceed to the third zone, where they become dehydrated and the cuticle becomes a smooth surface. This is caused by a mild oxidative process (gain of oxygen) that changes the cystine linkages to disulfide bonds, which in turn strengthens the hair cuticle.
The catagen stage is a very short phase (a few weeks to a few months) that begins the transition from growth (anagen) to resting (telogen). During this step, the cell division slows down in the follicle and the bulb begins to migrate to the surface.
Now the bulb has moved far enough away from the blood vessels that it can no longer receive nutrients. Growth is halted and the bulb has reduced in size, allowing a new root to start developing. This new root is beginning the anagen phase and helps to push the old hair completely out of the follicle.
Remember sweet, postpartum Cassie? During pregnancy, hormonal shifts prevented her hair from entering the telogen phase, and thus her hair became thicker. However, this hormone shift is short-lived. After delivery, the hormones shift again, and all the hairs that did not shed while pregnant will shed, AND all the hair “scheduled” to shed at that time will shed simultaneously. And, thus postpartum baldness arrives. Make sure you have a hair catcher down in the shower(!)
Many factors can affect hair growth cycles. One way you may be able to turn the tide in your favor is through regular scalp massage. This stimulates blood flow to the scalp and aids in hair growth. Here are two scalp massagers we like:
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