The actress, 47, shared a photo of her new salt-and-pepper buzz cut on Instagram.
“I cut my hair short to transition myself and my son for impending baldness. Easy. Baldness came,” Blair wrote in the caption. “I didn’t shave head to that end. Of course it fell out. Shiny. Pale dome. Nice enough. It took two months to begin regrowth.”
When her hair started to grow again, it “came in fine and pale and very sparse,” she continued. “I shaved it. It looked too sad. For me.”
She tried dyeing it brown, but she ended up just coloring her scalp, so she decided to cut it shorter with clippers.
“A few weeks later, here we are,” she wrote. “A thinnish, patchy charcoal head. I will see how a pixie grows in. Or I will buzz again. It seems to be too much to have long hair again. So I will leave it short and gray, something I have never before wanted to do.”
“I equated it with giving up,” she added. “And maybe giving up long, brown hair, complete with time consuming and expensive highlights and lowlights isn’t necessarily a give up. Give in. Embrace. Sure. I’ll try it.”
Since she was diagnosed with multiple sclerosis last year, Blair has shared honest, moving updates about her daily life with the condition.
She revealed that she underwent chemotherapy after her body didn’t respond to other treatments.
“I was really declining more rapidly than I found acceptable,” she said at the Time 100 Health Summit last month.
At first, she was resistant to the idea of chemotherapy.
"I was like, 'I'm not ruining my body — what's left of it — why would I put this horrible drug in my body?'" she said.
However, she felt that she was “kind of out of options” and agreed to a microdose of chemotherapy, which she said immediately offered relief from her symptoms.
“So I was like, ‘Maybe I just have too much junk in there. And that killed some junk,’” she said. “Like what do I care if it kills my whole body because my whole body is like, one big macrophage of yuck!”
When Blair posted the most recent photo celebrating her post-chemo hair, she was flooded with comments of support, including a sweet note from Gwyneth Paltrow.
“You have never looked more beautiful as these last months,” Paltrow wrote in the comments.
Blair is proudly rocking her new, natural buzz cut, though she added jokingly she would consider coloring her hair again if “some fancy pants company with a thick checkbook wants to entice me out of dye retirement.”
“Then I will sing about the glories of processed hair! I certainly will,” she wrote.