Dandruff Hurts AND Also Helps Our Hair Loss?! (Explaining the Science)

Added: 2026-05-18

[00:00:00]Did you know you can make a scientific argument that having dandruff can both help your hair loss and hurt your hair loss? It just depends on which mechanistic argument you'd like to propose. In this video, we're going to dive into the real clinical literature, explore these arguments, and tell you what to do if you have dandruff, you have hair loss, and you want to maximize your treatment outcomes. And for those new here, my name is Rob English. I am a researcher who focuses on hair loss disorders. I'm on the editorial board of a dermatology journal. I publish papers related to hair loss and I make videos like this to help individuals who are fighting hair loss and looking for a path forward based on the evidence.

[00:00:42]Now, dandruff is incredibly common. If you've ever noticed tiny white flakes on your hair strands or maybe on your pillowcase or perhaps on your darker shirts after a long day, chances are that you've had some degree of dandruff and you're not in bad company. To give you an idea of just how common dandruff is, we can talk about one of the most common conditions associated with dandruff, sebereetic dermatitis, and its prevalence in the general population. At a visual level about 5% of adults will present with some degree of sebereetic dermatitis. This is that redness, itching and scaling that we can see in skin. But if you zoom in with some sort of microscopic device and you just look at individuals with the most common kind of hair loss by which people seek treatment, that's androgenic alopecia.

[00:01:30]Then in these adults up to 60% of them have some subclinical markers linked to serereetic dermatitis. That can be arborizing blood vessels, white scales, yellow flakes, and skin gradient changes indicative of some lowgrade inflammation. So it stands to reason that dandruff is very common. At a cosmetic level, it presents very frequently. But at a subclinical level, most people facing some degree of hair loss as adults might have it. And because of this, we have to ask the question, what kind of impact might having dandruff have on your hair loss treatments? You might think, Rob, why are you even asking this question? Who cares? I mean clinical studies show that FDA approved medications like finasteride and minoxidil work for the overwhelming majority of people with androgenic alipcia. Drugs like finasteride slow stop or partially reverse hair loss in 80 to 90% of the men who use it. And drugs like topical minoxidil they might have slightly lower response rates but the combination of the two according to clinical research really works well and for most people.

[00:02:36]So what does dandruff have to do with any of this? Well, you'd absolutely be right to think this, except if you dig into the clinical studies supporting those claims and look at the inclusion and exclusion criteria in those participants, we would realize that our definition of androgenic alipcia related response rates to treatments is actually derived from individuals in these studies who were excluded if they had things like seretic dermatitis or moderate cases of scalp eczema or scalp psoriasis or anything else that could potenti potentiate a chronic case of dandruff. And that's actually kind of problematic because depending on how you decide to define if you have something like sebetic dermatitis, which at a visual level has a 5% prevalence in adults, but at a subclinical level in androgenic alipcia sufferers has a 55% prevalence. Now you have a situation where those clinical studies on those drugs that establish our response rates, they might not actually reflect the general population of people who actually take them. those who have probably higher levels of dandruff than the participants selected for in those studies. So then we need to ask does having dandruff, which is basically just a byproduct of some scalp inflammation, does this dandruff make our hair loss worse? And does dandruff worsen our ability to respond to hair loss treatments? And this is where we see research groups make multiple arguments both for dandruff hurting our hair loss outcomes and then possibly for dandruff helping our hair loss outcomes. We're going to get into all of those and then we'll talk about what the clinical studies which are limited actually suggest.

[00:04:16]First, dandruff can build a layer of debris that might block our ability to absorb hair loss topicals. Dandruff is effectively skin flaking caused by excessive inflammation or cellular production in the outermost layers of our skin. That's our epidermis and more specifically our stratum corneium.

[00:04:33]That's the layer of skin that helps determine what can get into our skin and escape our skin. And as inflammation and cellular production here builds, you can create debris like those white scales and yellow scales we see in those micro zoomed photos. And with just minor flakes, you're probably not going to block a lot of topical being applied to the scalp. But if you have major flaking, which we can see in a lot of these micro zoomed photos that we assess, you'll actually see that those flakes get in the way of being able to reach the scalp skin itself. And you have to have a hair loss topical touch the real scalp skin in order to then enter into the skin where it can reach the hair follicles and have an effect.

[00:05:13]And if it can't do that, you're not going to get a good outcome. So in this case, you can argue that the skin flaking from dandruff in moderate to severe cases is bad. It hurts your ability to respond to topicals because it blocks the topicals from reaching your actual scalp skin. But then there's also research to suggest that dandruff might also be good for hair loss treatments, which can sound crazy, but allow me to explain.

[00:05:39]When you have dandruff and increased cell turnover at the epidermis, you can also actually increase the ability for topical ingredients that you're applying to penetrate into the skin. Because ironically, dandruff from conditions like attopic dermatitis in clinical research is shown to actually increase the size of the molecules that can bypass from outside of the skin into the skin and thereby reach our hair follicles. You can see this in this chart. For normal skin, skin penetration capacity tends to drop off for molecules that are around 400 to 500 daltons and then it becomes nearly impossible in normal skin for molecules bigger than 600 dlins to penetrate. But then that same modeling shows that skin affected by attopic dermatitis that AD because of this damage to your stratum corneium, it means that bigger molecules can actually get through. Now here are the molecular weights for common hair loss drug topicals like minoxidil, finasteride and dutastasteride. So for dutastasteride especially you can make this hypothetical argument that in dandruff affected skin when you apply this drug you actually get a better opportunity for it to absorb and that perhaps maybe for all drugs maybe more of the total medication will reach into your hair follicles because of this increased scalp permeability caused by excessive cell turnover from the dandruff. So now we have this equation we need to wait is the flaking that you get from dandruff which should block hair loss topicals from reaching the skin is that offsetting the increase in scalp permeability from when you have a lot of flaking from dandruff and now topicals can actually escape more quickly into the scalp skin. And then you also now need to ask, does this increased skin permeability and bigger potential drug exposure also increase the risk of side effects from applying a hair loss topical? Because with more skin penetration, often more drug is going to escape from outside the skin into the skin, but then also into your bloodstream, which will increase your systemic exposure to that drug. And so people applying hair loss topicals, they're often doing this because they'd like to avoid systemic drugs in the first place. So now we have to worry about this side effect risk as well and this is a problem. So now we have multiple arguments by which scalp dandruff might hurt our ability to regrow hair but then also help our ability to regrow hair but also increase our risk of side effects from topicals.

[00:08:01]So what is the truth here? What does the actual clinical evidence say? Well, there is a study that best approximates an answer. Let's dive into it and find out.

[00:08:11]In the early 1990s, a hair loss research juggernaut Dr. Whiting did a study on scalp biopsies related to androgenic alopecia. Individuals applied topical minoxidil and then after the study those individuals were biopsied and then their response rates to minoxidil were evaluated against what the biopsies showed for their skin. What Dr. Whiting found amongst many other things was that individuals who had markers in their biopsy for scalp inflammation, those individuals saw lower response rates for topical minoxidil than if somebody's biopsy showed they had no scalp inflammation whatsoever. The conclusion here was that even mild or subclinical cases of scalp inflammation can actually hurt our ability to respond to hair loss treatments like topical minoxidil. And this is important because dandruff is an expression of scalp inflammation. So if you do have dandruff in this case, your ability to respond to hair loss topicals on balance, waiting those arguments for and against, it's likely that they slightly hurt your outcomes rather than help your outcomes. And it's also for this exact reason why at Ulo, the teleahalth brand that we founded, we went to great lengths to formulate our hair loss topicals without things that might trigger or exacerbate scalp inflammation. First, we formulated all topicals without propylene glycol, and that's a common skin irritant that can trigger scalp inflammation or itchiness in up to 7% of users. And it can also exacerbate underlying dandruff. And then secondly, during our intake forms, we also ask if an individual has any symptoms associated with scalp inflammation so that if it's present, we can go a step further and recommend formulations of topicals without additional ingredients like tininoan or retinoic acid. And for most scalps at low doses, tininoan is not an issue. It just greatly enhances the impact that minoxidil can have on your hair. But for those with obvious dandruff or dermatitis, tininoan can and often will agitate this underlying inflammation. It can make your dandruff worse, which according to Dr. Whiting's research isn't going to help your hair situation very much. So, we like to mitigate these risks during your intake so that if you have any scalp inflammation markers, you're not recommended formulations with propyline glycol, which we don't make at all, and then tininoone, which we would conditionally eliminate in your final RX recommendation pending your prescriptions. And of course, once somebody eliminates any underlying scalp inflammation causing the dandruff, they can then better tolerate those ingredients and introduce them. We'll get to that in just a second. But the long story short is that dandruff not only hurts our ability to respond to hair loss topicals like minoxidil, but it also limits the topical ingredients that we should be putting on our scalps in the first place. So that's conclusion number one and two. But conclusion number three is that while your dandruff at subclinical levels could blunt your ability to respond to hair loss topicals, it only will actually contribute to you losing more hair if it's very extreme. Because keep in mind that dandruff isn't this binary metric.

[00:11:13]It's not you have it or you don't. It occurs on a gradient from barely noticeable to severe or accelerating underlying androgenic alipcia. But as you move in that scale in severity from subclinical to clinical to severe, this is where you start to see dandruff from sebereetic dermatitis actually causing your hair to shed quite a bit. the inflammation surrounding the hair follicles just gets too significant and the hairs will start to shed prematurely causing what's known as a teligen ofluvium shed. This is typically temporary. But if you have underlying androgenic alopecia, that shed can now feed into that hair loss disorder and accelerate its advancement because it will create faster hair cycling that without treatment will resolve to hair follicle miniaturization that's chronic and progressive in subsequent hair cycles. So the big picture here, minor cases of dandruff are not causing your hair to fall out in spades. Severe cases that are prolonged and consistent absolutely can.

[00:12:18]Above all, what we can derive from the totality of clinical evidence on dandruff and hair loss is that it's a minor problem for most people, but it is a major problem for a select few. And if you're trying to get the best possible outcomes from your hair regrowth regimen, you really probably should do your best to treat your dandruff as well. The good news here is that in almost all cases, dandruff is a fixable problem. It can be caused by such a myriad of things. reactions to topical ingredients, microorganisms growing on your scalp like malisthesia, excessive sebum production due to the higher androgenic activity in your scalp which causes the growth of sebaceous glands and an increase in the scalp oils you produce. Diet and lifestyle choices that can change the composition of the scalp oils you secrete which can then overfeed those pathogenic microorganisms. Even autoimmune reactions, these are all triggers and contributors to dandruff.

[00:13:12]And yet each of these things can be targeted systematically to improve your situation. You can remove problematic topical ingredients. You can kill off bad microbes with ketoonazol shampoo.

[00:13:22]You can control hormones like DHT with five alpha reductase inhibitors like finasteride, dutasteride, or even topical androgen receptor antagonists.

[00:13:30]You can stop eating so much dairy or processed foods to control the type of oil that your sebaceous glands secrete.

[00:13:37]You can shrink your sebaceous gland sebum output with lowd dose oral isotininoonean. And if needed, you can use other drugs and anti-inflammatory approaches to mitigate autoimmune reactions in your scalp. From the temporary use of topical corticosteroids to even trying things like zariv foam.

[00:13:54]These all can help. And when you stack many of them together, you can often make dandruff a problem of the past. For more information on this, watch our video on seereetic dermatitis. Read our guides on the same subject. we deep dive there and talk about protocols that are supported by the clinical literature.

[00:14:10]So, there's a lot you can do here. Do not feel disheartened if your first attempts to treat dandruff aren't a home run. Oftentimes, that's the case, but with trial and error, you can totally get this improved, at least for the majority of people.

[00:14:24]And one last piece of advice, when you're treating hair loss and dealing with dandruff, yes, your ability to respond to topicals, it's going to be a bit lower, but you can still use topicals. Just know that your treatment response will be greatly improved once you fix the dandruff problem. And in the interim, possibly a bestin-class approach would be to prioritize more oral hair loss treatments that at least ensure that especially more severe cases of dandruff, those ingredients are actually penetrating properly into the skin, reaching your scalp, reaching the hair follicles, all of that stuff.

[00:14:56]Because again, you can make a hypothetical argument that dandruff helps your hair or it hurts your hair.

[00:15:02]But the best data that we have so far suggests that it slightly hurts our ability to respond to hair loss topicals, which means prioritizing oral hair loss treatments might make more sense, at least until you get rid of it.

[00:15:15]Okay, that's everything. Thank you for watching. That's all. I will see you next time.