Threads Stimulate Hair Regrowth

Using polydioxanone (PDO) threads is a relatively painless lunchtime procedure that can stimulate hair regrowth for six or more months in men and women with androgenetic alopecia.

Alan J. Bauman, M.D., who pioneered and trademarked the PDO thread insertion procedure PDOgro for hair regrowth in the U.S., has been performing the procedure for more than two years. He presented results from research on PDOgro and did a live interactive hair restoration session at the South Beach Symposium for Clinical and Aesthetic Dermatology in Miami, Fla., in 2019.

PDO is a slowly absorbing synthetic surgical suture material that stimulates collagen production, elastin, hyaluronic acid and new blood vessel formation. It also activates fibroblasts while it dissolves. FDA-cleared PDO sutures have been used safely in surgery for decades, according to Dr. Bauman.

“When you put PDO into the body as a deep suture, it lasts for more than six months. In the aesthetic world, they’ve been using these really thin, fine filaments of PDO very superficially in the skin to trigger tissue regeneration and repair,” Dr. Bauman says.

An aesthetic colleague asked Dr. Bauman if he had considered using these threads in the scalp, explaining that studies had shown that an unexpected result when using the threads for facial rejuvenation was a boost in hair growth in treated areas of hair-bearing skin.

In fact, there are studies suggesting the threads result in noticeable hair growth. Indian researchers evaluated the efficacy and safety of PDO thread insertion into the scalp in a small study of men with androgenic alopecia. They found that at 12 weeks, all five patients had appreciably increased hair counts, according to a letter to the editor published in 2015 in the Journal of the European Academy of Dermatology and Venereology.¹

“Although the exact mechanism of action of hair growth stimulation by PDO threads remains speculative, it is likely to be similar to that of microneedling, involving enhanced expression of hair‐related genes, release of growth factors like PDGF and direct activation of stem cells in the hair bulge area,” the authors write.

Monofilament thread treatment also significantly improved hair mass index and hair counts in a study of women with female androgenetic alopecia, researchers reported in March 2020 in the Journal of Dermatological Treatment.²

Dr. Bauman says he initially performed the procedure on a small cohort of male and female patients with thinning or receding hair in 2018.

“We did it without any other therapy. These monotherapy patients were exclusively ‘virgin’ and had used no other treatments previously. We tried it in different areas. For example, one woman had thinning in the crown and another woman had a receding, thinning hairline and temple area,” Dr. Bauman says.

Every one of the first six patients treated some visual improvement within 6 to 12 weeks of the PDO thread insertion.

Dr. Bauman then rolled it out to patients who were interested in using PDO threads for hair growth either with or without other treatments. He has treated nearly 100 patients so far.

Dr. Bauman says he uses cross-sectional hair bundle trichometry (HairCheck) in several areas and global photos for tracking. In this cohort, Dr. Bauman has used primarily a combination of PDO threads with dual-spin platelet-rich plasma (PRP) to optimize results.

“We’ve seen nearly 90% improve or maintain their Hair Mass Index within six months of treatment and patient satisfaction has been excellent for this quick and comfortable ‘lunchtime’ treatment,” he says. “Recently, it has been a little difficult to track some of these patients through the shutdown to tell how long these results are lasting. Threads typically last in the body for 6 to 12 months. We imagine that it will be similar for the hair — about 6 to 12 months before we need to redo it.”

Ideal Thread Candidates

Patients need to have hair follicles for PDO threads to work.

“Just like with PRP, if there’s no follicle in the skin in that area, you’re not going to get a new follicle to reappear,” Dr. Bauman says. “It’s a good idea to do some measurements. Use your microscope and really get down and dirty to see how much vellus hair, terminal hair and miniaturized/intermediate hair density you have in each zone. Intermediate or miniaturized hair is likely what could be rejuvenated. If the area looks like it has been severely depleted, meaning the follicle density is shot, then the treatment probably isn’t going to do much except maybe protect what the patient has.”

Dr. Bauman says he has seen the most robust improvement in cases where he treated women and men with high numbers of weak (intermediate) hairs.

“People in the earlier stages where hair is just beginning to thin are ideal,” he says.

NEXT: Best Practices for Hair Regrowth with PDO Threads