Why does chemotherapy change the texture of hair that grows back after treatment?

Bun

There has been many a documented case of a person's curl pattern changing after chemotherapy. A person with straight blonde hair may regrow dark, curly hair after chemo, while others with kinkier hair may experience a loosening of texture, both a direct result of a phenomenon known as "chemo curls."

As a scientifically minded individual, I decided that I really wanted to know WHY it is that chemo curls occur.

Asking the Experts

My first stop was to ask Dr. Kari Williams, trichologist and owner of Mahogany Revolution Salon in LA. I wasn't expecting a simple answer in regard to this complex matter, so I was a bit perplexed by her simple response: "There is no detailed scientific understanding of why this happens."

I was frankly a bit surprised to hear that, despite confirmation that chemotherapy effects the hair follicle dramatically, there remains no scientific clarity as to why chemo curls occur.

I decided to dig a bit further, reaching out to a graduate researcher to help me source some medical journals. I found one particularly intriguing article that discussed how certain drugs have known affects on hair (and nails), including chemotherapy.  However, this article also ended on an inconclusive note: "The exact mechanism of this drug-induced textural change remains unknown at this time."

The end. Color me stumped.

A Possible Theory

Fortunately, I remembered that, when there's a dearth of fact, there's often a plethora of theory. Harnessing the power of the Internet, I called on one of hair's scientific champions, JC of The Natural Haven.

Not that I was expecting a simple answer in regard to this complex matter, but I was a bit perplexed by her simple response, "There is no detailed scientific understanding of why this [chemo curls] happens."

As a PhD of Material Science, JC's research relies heavily on academic articles and journals, and I thought she might find something for me to work with. Her hypothesis holds that chemotherapy, a cocktail of drugs that work to disable the multiplication of frequently dividing cells, such as cancerous cells, is unable to discern some good cells from cancerous cells. As a result, other frequently dividing cells — hair, skin, and nail cells — are often found in the crosshairs of chemotherapy, and the treatment causes them to behave differently than they normally would.

Hair loss and brittle hair are a common example of the effect chemotherapy can have on non-cancerous hair cells. However, most cancer survivors know that their hair DOES grow back once chemotherapy stops due to the miraculous ability of cells to repair themselves.

Changes in hair thickness and texture (aka. chemo curls) are possible results of a slight change in the DNA of the cells that are repaired. Once chemotherapy completely exits the body, all cell production usually reverts back to what it was pre-chemo.

Want More?

We might not know the science behind what is going on, but we do know the women who have been through it! Get the personal side to chemo curls, and how this woman survived the ordeal. 

Final Thoughts

There you have it!  A possible answer to the chemo curls mystery.  I will note that it is interesting that there is a lack of research and information supporting why certain drugs have these physical manifestations on the body, however I have a hunch that doctors and researchers are more focused on the eradication of the diseases in general.