Does dandruff cause hair loss? What the studies found, and what people were told

Dandruff and hair loss often turn up together, and people want to know if one causes the other. This page puts two things side by side: what the research on dandruff, seborrheic dermatitis (“seb derm”) and anti-dandruff shampoos found, and what commenters said in 826 reddit threads (2013–2026) about dandruff and hair loss, anti-dandruff shampoos, flakes from minoxidil and flakes after a hair transplant.

In short: no study we found shows that dandruff causes the common, genetic kind of hair loss. A few studies link the two: in identical twins, the twin with dandruff had more hair loss at the front, and in a small 5-year study, men with worse dandruff had more hairs in the resting (shedding) phase. These are associations from small or observational studies, not proof. Anti-dandruff shampoos cut shedding in one study but did not change hair density; one trial found a small gain in hair count from a zinc pyrithione shampoo, less than half of minoxidil's. On reddit, in 152 threads where someone asked and got an answer, commenters were split: “no, it’s genetic hair loss” in 20%, “it can cause some shedding, mostly temporary” in 34% and “yes, it causes or speeds up hair loss” in 34%. Anti-dandruff shampoos were mostly called fine, with a warning that they can dry the hair.

What the studies found

The contribution of endogenous and exogenous factors to male alopecia: a study of identical twins

Gatherwright J, Liu MT, Amirlak B, Gliniak C, Totonchi A, Guyuron B · Plast Reconstr Surg, 2013 · 92 identical male twins (recruited 2009-2011), questionnaire + photographs, hair loss compared within twin pairs. An observational association study (level of evidence III); dandruff was one of many self-reported factors tested, so it shows a link, not that dandruff causes the loss. PubMed abstract only; the full text is paywalled and was not fetched. No funding statement in the abstract.

  • 92 identical male twins filled in a questionnaire and were photographed; hair loss was compared between the twins of each pair. “Ninety-two identical male twins were recruited from 2009 to 2011. A comprehensive questionnaire was completed followed by the acquisition of sputum samples for testosterone analysis and standardized digital photography.”
  • The twin with dandruff tended to have more hair loss at the front (an association, p = 0.028). “Increased smoking duration (p < 0.001) and the presence of dandruff (p = 0.028) were significantly associated with increased frontal hair loss.”

Dandruff-associated smouldering alopecia: a chronobiological assessment over 5 years

Piérard-Franchimont C, Xhauflaire-Uhoda E, Loussouarn G, Saint Léger D, Piérard GE · Clin Exp Dermatol, 2006 · Only 8 men with chronic dandruff, each examined 40 times over 5 years (hair counts and trichograms on the dandruff-affected parietal scalp). No control group in this study; a correlation, not proof of cause. PubMed abstract only; full text paywalled and not fetched. Funding and co-author affiliations beyond the first author are not stated in the abstract.

  • The authors write that in some people dandruff keeps coming back, and that excessive shedding and diffuse thinning may develop. “In some individuals, dandruff may be recurrent and even chronic. This represents a difficult-to-treat condition. Excessive hair shedding and diffuse alopecia may develop.”
  • The study followed just eight men, 40 visits each over five years. “This study was performed in eight men suffering from such a scalp condition. They were examined 40 times at regular intervals for five consecutive years.”
  • The worse the dandruff, the higher the share of hairs in the resting (shedding) phase. “A positive correlation was found between the percentage of telogen hairs and dandruff severity as assessed by the squamometry index.”
  • Dandruff, resting hairs and hair loss rose and fell in a twice-a-year rhythm, but the authors say that rhythm is not fundamentally different from people without dandruff. “The biorhythms on the hair cycle in dandruff are not fundamentally different from those previously reported in subjects without dandruff.”

Nudging hair shedding by antidandruff shampoos. A comparison of 1% ketoconazole, 1% piroctone olamine and 1% zinc pyrithione formulations

Piérard-Franchimont C, Goffin V, Henry F, Uhoda I, Braham C, Piérard GE · Int J Cosmet Sci, 2002 · 150 men with shedding linked to androgenic alopecia plus dandruff, randomly given one of three anti-dandruff shampoos for 6 months. There was NO placebo or no-treatment group, so the drop in shedding cannot be separated from time or chance. Shedding was scored semi-quantitatively. Published in a cosmetic-science journal. PubMed abstract only; funding not stated in the abstract.

  • The authors start from earlier reports that dandruff and seborrhoeic dermatitis affect shedding and thinning. “Hair shedding and hair thinning have been reported to be affected by dandruff and seborrhoeic dermatitis.”
  • 150 men with dandruff and shedding linked to male-pattern loss each used one of three anti-dandruff shampoos 2-3 times a week for 6 months. “The present study was conducted in 150 men presenting with telogen effluvium related to androgenic alopecia associated with dandruff. They were randomly allocated to three groups receiving each one of the three shampoos in the market containing either 1% ketoconazole (KTZ), 1% piroctone olamine (PTO) or 1% zinc pyrithione (ZPT). Shampoos had to be used 2-3 times a week for 6 months.”
  • All three cleared the dandruff and itch quickly. “The three treatments cleared pruritus and dandruff rapidly.”
  • After 6 months hair density had NOT changed, though shedding during washing was 10-17% lower. “At end point, hair density was unchanged, although hair shedding was decreased (KTZ: -17.3%, PTO: -16.5%, ZPT: -10.1%)”

Increased hair shedding may be associated with the presence of Pityrosporum ovale

Nematian J, Ravaghi M, Gholamrezanezhad A, Nematian E · Am J Clin Dermatol, 2006 · Cross-sectional study of 300 medical students in Tehran: scalp scrapings checked under a microscope for Malassezia (the yeast linked to dandruff), compared between students with and without shedding (by history and hair-pull test). It looked at the yeast, not at dandruff itself, and shows an association only; the authors call for a larger study. PubMed abstract only; funding not stated.

  • Malassezia yeasts have been suspected as the cause of dandruff for over a century. “Malassezia fungi have been the suspected cause of dandruff for more than a century.”
  • Students with shedding far more often had the yeast on their scalp. “The prevalence of positive smears was significantly higher among subjects with hair shedding than among normal subjects (89.92% vs 9.52%, p<0.001).”
  • The authors only say this raises the possibility of a link, to be checked in a larger study. “our results therefore raise the possibility of a relationship between this unicellular organism and hair loss. Our study findings should be explored in a larger series of patients.”

The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial

Berger RS, Fu JL, Smiles KA, Turner CB, Schnell BM, Werchowski KM, Lammers KM · Br J Dermatol, 2003 · Randomized, investigator-blinded trial, 200 men aged 18-49 with Norwood III vertex or IV balding, 26 weeks; run by a contract research organisation (Hill Top Research). The abstract does not say the men had dandruff and states no funder; a later review co-written by P&G employees (source 7) names the test shampoo as Head & Shoulders (Procter and Gamble). PubMed abstract only.

  • 200 men with male-pattern balding were randomized to a 1% zinc pyrithione (anti-dandruff) shampoo, 5% minoxidil, a placebo shampoo, or both, for 6 months. “The purpose of this 6-month, 200-patient, randomized, investigator-blinded, parallel-group clinical study was to assess the hair growth benefits of a 1% pyrithione zinc shampoo.”
  • The shampoo raised hair counts versus placebo, but by slightly less than half as much as minoxidil. “The relative increase in hair count for the 1% pyrithione zinc shampoo was slightly less than half that for the minoxidil topical solution and was essentially maintained throughout the 26-week treatment period.”
  • Adding the shampoo to minoxidil gave no extra benefit. “No advantage was seen in using both the 5% minoxidil topical solution and the 1% pyrithione zinc shampoo.”
  • The men themselves did not clearly notice the shampoo's effect; only the investigator tended to (not statistically significant). “The benefit of the 1% pyrithione zinc shampoo used alone tended (P < 0.1) to be apparent only to the investigator.”

Seborrheic Dermatitis and Dandruff: A Comprehensive Review

Borda LJ, Wikramanayake TC · J Clin Investig Dermatol, 2015 · Narrative review by University of Miami dermatology researchers (open access, full text archived). Funded by the NIH (NIAMS AR059907) and University of Miami research awards; no industry funding stated. A review, not new data.

  • Dandruff and seborrheic dermatitis are one condition on a spectrum: dandruff is the mild, scalp-only form without visible inflammation. “Seborrheic Dermatitis (SD) and dandruff are of a continuous spectrum of the same disease that affects the seborrheic areas of the body. Dandruff is restricted to the scalp, and involves itchy, flaking skin without visible inflammation.”
  • Dandruff is very common: about half of adults. “Comparing with SD, dandruff is much more common, and affects approximately 50% of the general adult population worldwide.”
  • Several factors together cause it: oil (sebum), yeast on the skin, and individual susceptibility. “Various intrinsic and environmental factors, such as sebaceous secretions, skin surface fungal colonization, individual susceptibility, and interactions between these factors, all contribute to the pathogenesis of SD and dandruff.”
  • Oil production alone does not decide who gets it. “These findings suggest that while SG activity strongly correlates with SD and dandruff, sebum production by itself is not a decisive cause.”
  • When telling it apart from fungal scalp infection (tinea capitis), the review says seborrheic dermatitis is not associated with hair loss. “Tinea capitis, a highly contagious disease, typically shows scaly patches of scalp hair loss associated with “black dots”, which represent distal ends of broken hairs [ 33 ]. Conversely, SD is not associated with hair loss.”
  • But its table of adult scalp seborrheic dermatitis describes a range up to crusts stuck to scalp and hair that lead to hair loss. “SD in Adults Scalp From mild desquamation to honey-colored crusts attached to scalp and hair leading to alopecia.”

Scalp Condition Impacts Hair Growth and Retention via Oxidative Stress

Trüeb RM, Henry JP, Davis MG, Schwartz JR · Int J Trichology, 2018 · Narrative review (open access, full text archived). Strong industry conflict: three of four authors are Procter and Gamble employees (P&G makes Head & Shoulders) and the first author consults for P&G; it ends by recommending zinc pyrithione shampoo for hair loss. It also says most of the evidence it summarises is observational. Treat its conclusions as the shampoo maker's position.

  • Three of the four authors work for Procter and Gamble and the fourth consults for it. “R. M. Trüeb is an active member of the Healthy Hair and Scalp Alliance and in this function provides consulting activity for Procter and Gamble. J. R. Schwartz, M. G. Davis, and J. P. Henry are employees of Procter and Gamble.”
  • The review says most of the published data linking scalp condition to hair are epidemiological comparisons against healthy-scalp controls. “Most of the published data are epidemiological in nature comparing hair obtained from individuals with dandruff or seborrheic dermatitis,”
  • It cites a number of observations suggesting the poor scalp health of dandruff and seborrheic dermatitis may cause premature hair loss. “a number of observations have found that premature hair loss may be caused by the poor scalp health associated with either dandruff and seborrheic dermatitis,”
  • It names the zinc pyrithione shampoo in the Berger trial (source 5) as Head & Shoulders, a Procter and Gamble product. “a 1% zinc pyrithione (ZPT)-based shampoo (Head & Shoulders ®, Procter and Gamble Company)”

Quotes are copied from the papers' abstracts and open-access full text (PubMed and PubMed Central), checked 17 Oct 2026. Things to weigh: the studies linking dandruff to hair loss are small (eight men in the 5-year study) or observational (the twins reported dandruff themselves), and the shampoo study had no placebo group. The 2015 review says two things that pull in different directions, and we show both. The 2018 review was written by people working for the maker of Head & Shoulders. We found no trial that followed people with and without dandruff to see who went bald.

What commenters told people who asked

276 threads asked whether dandruff or seb derm causes hair loss. Most came from people who had both (229); 47 asked in general. More were about seborrheic dermatitis (158) than plain dandruff (88). In 152 of them a commenter answered the question; in the rest, replies only gave scalp tips. The main answer per thread:

  • no, it’s genetic hair loss: 20% (31)
  • it can cause some shedding, mostly temporary: 34% (52)
  • yes, it causes or speeds up hair loss: 34% (51)
  • split: 12% (18)

It depended on what people had. For seb derm (93 answered threads), the most common answer was “it can cause some shedding, mostly temporary” (40%), and “no” was 17%. For plain dandruff (52), “yes” was 37% and “no” 27%.

Everything commenters said

Number of the 276 threads where at least one top comment said it:

  • 173treat the scalp: ketoconazole, zinc pyrithione, selenium, ciclopirox, coal tar or a steroid lotion
  • 70see a dermatologist
  • 69seb derm or an inflamed scalp can cause some shedding or make loss worse
  • 63dandruff or seb derm caused or sped up their own hair loss
  • 52the loss is male-pattern hair loss: treat it (finasteride, minoxidil)
  • 46dandruff doesn’t cause male-pattern hair loss; genetics (DHT) do
  • 24shedding from seb derm is temporary and grows back once the scalp is treated
  • 20scratching or picking the scalp damages hair
  • 16ketoconazole (Nizoral) also helps hair loss itself
  • 12their hair came back after treating their seb derm

The most common reply was not an answer but advice: treat the scalp. Personal stories pulled one way: in 63 threads a commenter said dandruff or seb derm had cost them hair, and in 12 that hair came back once they treated it. These are people's own accounts; many also had genetic hair loss, so the two are hard to tell apart.

In commenters' words

“no, it’s genetic hair loss”

“it can cause some shedding, mostly temporary”

“yes, it causes or speeds up hair loss”

What people with both said

Some of the 229 askers, in their own words:

Do anti-dandruff shampoos cause hair loss? (Head & Shoulders, Nizoral)

119 threads asked whether an anti-dandruff shampoo, such as Head & Shoulders (zinc pyrithione), Nizoral (ketoconazole) or Selsun (selenium sulfide), causes hair loss or helps it, or which one to use. Commenters gave a view in 100:

  • fine, it doesn’t cause hair loss: 55% (55)
  • fine, but it can dry the hair and scalp: 31% (31)
  • stop using it: 5% (5)
  • split: 9% (9)

The warning that came up most was dryness: in 53 threads someone said these shampoos dry out the hair or scalp, and suggested using them two or three times a week with a conditioner. In 18 threads someone added that ketoconazole may help hair loss a little itself (what the studies say: ketoconazole shampoo and hair loss).

“fine, it doesn’t cause hair loss”

“fine, but it can dry the hair and scalp”

Flakes from minoxidil

285 threads came from people whose scalp started flaking or itching on minoxidil (a few on other topical treatments). This is the biggest group of all. The usual advice:

  • 154use an anti-dandruff shampoo (often ketoconazole) alongside it
  • 138switch to the foam or a propylene-glycol-free minoxidil
  • 65the flakes are dried minoxidil residue, not dandruff
  • 23go easy on drying shampoos; condition
  • 14see a dermatologist

Commenters' explanation: the flaking is often the liquid's propylene glycol or alcohol irritating the scalp, or dried residue, rather than dandruff. Commenters rarely told people to stop minoxidil (4 threads).

  • “when you apply too much minoxidil and your head doesn't absorb all of it, minoxidil (rogaine) will dry and make it look like its dandruff”
    A reply to Regaine causing dandruff? (reddit, Mar 2018)
  • “You will be alergic, or sensitive rather to the propylene glycol (PG) one of the ingredients of Minoxidil liquid”
    A reply to Dandruff after using minox? (reddit, Feb 2021)
  • “I was complaining about the flaking and redness from the liquid min until my brother convinced to switch to foam which helped tremendously.”
    A reply to Combating dryness and flakes from minoxidil (reddit, Jul 2019)
  • “I used to have dandruff when I used minoxidil twice a day, so I started using it once a day and it stopped my problem.”
    A reply to Redness and flaking from topical minoxidil (reddit, Jan 2025)

What people reported from minoxidil itself: minoxidil results.

Flakes and seb derm around a hair transplant

146 threads were about flakes, scabs or seb derm around a hair transplant: mostly flakes in the weeks after surgery, and some from people with seb derm asking whether they can have one.

Flakes after surgery: usually normal

Seb derm and medicated shampoos: get it under control, ask your clinic

Your own surgeon's instructions come first. More on the months after surgery: hair transplant recovery, month by month.

How this page was made

We took every live reddit thread in our corpus whose title names dandruff, seborrheic dermatitis, flakes, Head & Shoulders, Selsun or zinc pyrithione, and read the asker's post and the top comments by other people. Threads about something else (skincare with no hair question, flakes from microneedling, memes) are not counted. Each quote is copied word for word from the comment or post it links to; we picked them by hand so each states the view it is shown under. Each study quote is copied from the archived abstract or full text. Removed posts are left out, usernames are not shown, and posts that mention suicide or self-harm are never quoted. Data as of Oct 2026. This is not medical advice: a scalp that is red, weeping or losing hair in patches is one for a dermatologist.

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