Broccoli compound helped lab cells break down a hair-loss hormone

Researchers at Shiga University of Medical Science in Japan say a natural compound found in broccoli may help the scalp clear away a male hormone linked to pattern baldness. The work, reported on November 4, was done on scalp tissue samples and on cells grown in the lab. It has not been tested on hair growth in people.¹

The compound is sulforaphane. In lab-grown cells, it raised the levels of enzymes that break down DHT (dihydrotestosterone), a hormone known to play a major role in age-related hair thinning.¹ The team frames this as a different strategy from today’s medicines, which mostly try to stop the body from making DHT in the first place.¹

What the team reported

Scientists still do not fully understand why hair thins with age. DHT is known to be a big part of it.¹ Medicines for male pattern baldness, called androgenetic alopecia or AGA, usually work by blocking the process that produces DHT.¹ In that process, an enzyme called 5-alpha reductase turns testosterone into DHT, and drugs that block this enzyme are widely used to treat AGA.²

Those drugs can work, but Japan Forward reported that they may also cause side effects including depression, lower sex drive and impaired liver function, which have long worried patients and doctors.¹

The Shiga team asked a different question: does the scalp also have its own way of switching DHT off? They proposed that an “inactivation” system works alongside the system that activates the hormone, and that this cleanup system may weaken with age and add to hair thinning.¹

How they looked for it

The work had two steps, according to the report.

• Scalp tissue. The researchers first studied scalp tissue samples from people of different ages and both sexes, with different amounts of hair loss. They found a group of enzymes that can break down DHT in the sebaceous glands, the small oil glands next to hair follicles. In men, the levels of these enzymes went down with age.¹ The glands also held many receptors for male hormones, which the team said suggests the glands may help control the hormone balance of the scalp.¹
• Lab-grown cells. Next, the team added sulforaphane to cultured cells. Sulforaphane is known for its antioxidant effects and for its role in helping the body process harmful substances. In these experiments, it raised the levels of the DHT-breaking enzymes.¹

The researchers believe this suggests the compound could make up for the scalp’s natural defenses fading with age.¹

The study was led by Assistant Professor Yasuaki Ikuno of the university’s Faculty of Medicine. He has had pattern hair loss himself since his youth. He took medication for six years as a student and found it left him feeling unmotivated, which led him to think some people might want a different kind of treatment.¹

“In the future, topical treatments containing compounds such as sulforaphane may become a new option for addressing hair loss,” Ikuno said.¹

What it does not show yet

This is early lab work, and the gaps are large.

• No hair was measured. The report describes enzyme levels in tissue and in cells. It does not describe any test of whether sulforaphane keeps hair from thinning or helps it grow back.¹
• No people were treated. The sulforaphane experiments were in cultured cells only.¹
• Details are missing. The news report does not say how many tissue samples were studied, which cells were used, how much sulforaphane was applied, or whether the findings have been published in a peer-reviewed journal.¹
• Fewer side effects is a hope, not a finding. The team’s goal is treatments with fewer side effects than current drugs.¹ Nothing in the report compares side effects.

The finding that the enzymes decline with age in men comes from samples taken at one point in time from different people. That kind of comparison shows a pattern across ages. It does not show that the decline causes hair loss.

Who is behind it

Shiga University of Medical Science has filed a patent application based on the findings and is looking for company partners to bring the technology to market.¹ That gives the university a commercial interest in the idea moving forward. The report does not say who paid for the research.¹

Ikuno came to the project partly through his own experience with hair loss, and partly through a separate project on how stem cells age and how that relates to hormones.¹

How it fits with earlier broccoli research

The Shiga team is not the first in Japan to look at sulforaphane and hair. Researchers at Tokyo Medical and Dental University had earlier reported that sulforaphane helped hair regrow in a strain of obese lab mice by lowering DHT in the blood.² In those mice, they said, it boosted DHT-breaking enzymes, and they tied the effect to a cell defense pathway called Nrf2 that sulforaphane is known to switch on.² That is close to the mechanism the Shiga team now describes in human-derived tissue and cells.

The Tokyo group then ran a small test in people. It was a pilot trial, a small first test, in which healthy men aged 30 to 60 were randomly assigned to eat either broccoli sprouts, which are rich in sulforaphane, or alfalfa sprouts as a comparison, every day for one month. Neither the men nor the researchers knew who got which.² The paper describes 87 men being divided into the two groups and reports 68 enrolled, 34 in each group.²

The result did not match the mouse findings. Broccoli sprouts did not lower testosterone or DHT in the men’s blood. In the alfalfa group, those hormones rose.² The authors wrote that broccoli sprouts had no effect on blood hormone levels and that more research is needed to learn whether sulforaphane taken by mouth could help pattern hair loss.² That trial measured hormones in the blood, not hair, and it did not look at enzymes in the scalp.² The Shiga team’s own framing points toward a product put on the skin rather than food or pills.¹

Supplement sellers already link sulforaphane to hair. BrocElite, which sells a sulforaphane product, wrote on its blog in 2024 that research “continues to point to sulforaphane being an effective tool to promote hair growth,” citing a lab and scalp-sample study of a broccoli-family plant extract.³ That is a seller’s claim. Neither the new Shiga work nor the Tokyo trial tested a supplement’s effect on hair in people.¹²

What to watch next

The Shiga team says its next step is more detailed study using hair follicle models that include the oil glands, and testing other compounds that might work the same way.¹ Signs worth watching for:

• a peer-reviewed paper with the full methods and numbers behind the tissue and cell results;
• results from the follicle models, which would be closer to real hair than single cells;
• whether a company partners with the university on the patent;¹
• any trial in people that measures hair itself, not just hormone or enzyme levels.

Until then, the idea of helping the scalp break down DHT, rather than blocking it, remains a lab finding. It has not been shown to change hair growth in anyone.