The short answer is days to weeks. But there is a lot to learn about different products on the market and about the active and inactive ingredients they contain. Let’s start by defining what makes a “medicated shampoo.” In the 1980s the FDA wanted to weed out the snake oils of the shampoo world and so all products that were purported to help dandruff, seborrheic dermatitis and psoriasis were asked to submit data from clinical trials supporting the claims they were making.
When it came to treating seborrheic dermatitis, the following ingredients at certain percentages made the cut: pyrithione zinc, selenium sulfide, coal tar, and salicylic acid . Later the active ingredient ketoconazole was added to the list. When I say, “made the cut,” it means these ingredients (formally called “Active Ingredients”) had to prove they were both safe and effective. These 5 ingredients when made at the required percentage, with the appropriate labeling, and using factories that follow stringent manufacturing processes are called OTC (Over The Counter) medicated shampoos.
Medicated Shampoo Labels are important
When purchasing an OTC medicated shampoo for seborrheic dermatitis, you will notice a familiar appearing label on the back of the bottle or packaging called a “Drug Facts” label. This is also where you can easily identify which Active Ingredient is featured in each medicated shampoo. Some medicated shampoo brands make different product lines with different active ingredients. Read that label!
A few lines down from the top of that label you will find the subheading “Directions” and then the following lines that say something along the lines of, “For best results use at least twice a week or as directed by a doctor.” You may wonder why there are even different products on the market if the they all say the same thing? When claims for these active ingredients were evaluated in the 1980s, the experts weighed in and decided that if used with that frequency (two times per week) after a couple of weeks people would indeed see less flaking, scaling and irritation associated with seborrheic dermatitis. So yes, all OTC medicated shampoos do work to fight flakes.
So what distinguishes one medicated shampoo from another?
People react differently to different active ingredients. For example, one person may not like what their skin feels like with salicylic acid, while another person finds the smell of coal tar or selenium sulfide offensive. Some may find pyrithione zinc to be too gentle or ketoconazole to be too drying. Each brand of shampoo uses different active ingredients, and can do so at different percentages of active ingredient to deliver the active ingredient to your scalp and skin and accomplish the task at hand to improve the symptoms of seborrheic dermatitis and dandruff. It is similar to Tylenol and Ibuprofen, they both reduce fever and pain, but people have preference on which one works best for them.
Inactive Ingredients are important
A big distinguishing factor that we have yet to discuss is the inactive ingredient and the importance of what a medicated shampoo does not contain. Inactive ingredients are the crucial vehicles that make the product foam and help to wash away accumulated oils on the scalp and body. Many companies have added “natural” inactive ingredients that help to soothe or soften the skin or to moisturize the hair. And most products have scent or color, as many people find odors and colors a pleasing experience.
However, many adults with seborrheic dermatitis will describe themselves as having sensitive skin. Children have sensitive skin. These groups of people will benefit from avoiding products that contain common skin irritants like scent and color. These folks should look for a medicated shampoo that is fragrance free, dye free, paraben free, and sulfate free.
If you are an adult reading this article, you may have been surprised to see children mentioned in the paragraph above. Infants get “cradle cap.” Cradle cap is the scaling and flaking that occurs on the scalp and eyebrows. We see it in kids as young as 3-4 weeks old. Cradle cap is an infant version of seborrheic dermatitis. About 33% of kids persist with cradle cap through the age of 5 years old. 70 percent of pediatricians suggest using an OTC Medicated Shampoo to get rid of cradle cap. Until a couple years ago, there was no product created specifically with children in mind.
How long does it take to get rid of seborrheic dermatitis?
Some people may see results in as few as one or two washes. However, most will see significant improvement after 1 to 2 weeks of use. If there is much scale build up as you find in cradle cap you may need to use a medicated shampoo for seborrheic dermatitis daily for 3 to 7 days (Many OTC shampoos can be used daily as tolerated). People with thick scale build up, should consider leaving the shampoo on for 1-2 minutes before rinsing. People in this latter category should start to see results in 2-3 weeks. Once the scaling and flaking is under control, we suggest tapering use to 2-3 times per week.
- 358.710 Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis. PART 358 — MISCELLANEOUS EXTERNAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE. Code of Federal Regulations. Title 21, Volume 5. Revised as of April 1, 2019. CITE: 21CFR358.710 https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=358.710 . Accessed 9 April 2020.
However, most will see significant improvement after 1 to 2 weeks of use. If there is much scale build up as you find in cradle cap you may need to use a medicated shampoo for seborrheic dermatitis daily for 3 to 7 days (Many OTC shampoos can be used daily as tolerated).How many times do you have to use dandruff shampoo for it to work? ›
Shampoo at least one to two times a week until you notice improvements with your scalp. Once you see less dandruff, you need to shampoo a minimum of once a week, making sure to alternate between a dandruff shampoo, and a moisturizing shampoo.How many times a day should I use dandruff shampoo? ›
There's no limit to how often you can use Head & Shoulders – it's pH balanced and gentle on hair, so you can use it every day. You don't have to stick to exactly the same Head & Shoulders shampoo, either – mix it up!Why is my scalp still flaky after using dandruff shampoo? ›
If you've been using a dandruff shampoo for several weeks but still have dandruff, it may be time to see a doctor. You should also see a doctor if your scalp is swollen or red, if your hair is falling out, or if you have a red, scaly rash on other parts of your body.Why my dandruff is not going after shampoo? ›
It could be that you don't use enough shampoo, or that the shampoo you use isn't strong enough to break down the oil barrier that is contributing to your dandruff. The remedy: While the fix could be as simple as shampooing more frequently, you might need to take it one step further.Does dandruff go after one wash? ›
You should wash your hair more often.
Kaplan, M.D. To rid your scalp of dandruff, you need to clean out all the gunk, which a regular shampoo won't do. Dr. Kaplan recommends a medicated dandruff shampoo (which you can find at drugstores) every day, one that contains ketoconazole, selenium sulfide, or zinc.
Scratching can increase irritation and lead to a vicious cycle. When you touch and scratch, you can also introduce dirt into the mix that can make dandruff worse. Find the right shampooing balance for your scalp.What is the main cause of dandruff? ›
Dandruff may have several causes, including: Irritated, oily skin. Dry skin. A yeastlike fungus (malassezia) that feeds on oils on the scalps of most adults.How often should I shower if I have dandruff? ›
The frequency of shampooing necessary to control dandruff varies from person to person. Some need to shampoo twice a week, others more frequently, even daily. Many people forget that the scalp as well as the hair needs to be shampooed.Why is my scalp so itchy but no dandruff? ›
Various underlying conditions, such as head lice, hives, or dermatitis, can all cause an itchy scalp. Scalp pruritus, or an itchy scalp, is a common health issue that many people experience.
If you're prone to dandruff, make sure to use an anti-dandruff conditioner as the final step in your wash routine. While products won't cause dandruff itself, they could make some scalp conditions worse. So try a few products out to see which ones work best for you.Does scratching dandruff make it worse? ›
The most common mistake that people with a flaky scalp make is scratching their scalp vigorously. The temporary relief is sure to aggravate the condition more, with the possibility of a scalp infection. Resist the temptation, no matter how itchy it gets.What can be mistaken for dandruff? ›
Sometimes, what seems to be dandruff might indicate another underlying skin condition, such as seborrheic dermatitis, eczema, psoriasis, or fungal infection. A person should seek medical treatment for dandruff if symptoms are severe or do not resolve with over-the-counter (OTC) shampoos and ointments.Does hot water cause dandruff? ›
Hot water can also cause inflammation on the scalp, which can lead to dandruff, itchiness and hair loss. This occurs because hot water damages the hair follicles and disrupts the natural balance of the scalp.Does shampooing twice help dandruff? ›
It's not needed every time you wash your hair, but shampooing twice gives you a deeper cleanse that could be beneficial if you have a build-up of product, you've been swimming in the ocean, or if you have dandruff and need the extra wash to lift away flakes.How many times do I have to use head and shoulders to get rid of dandruff? ›
Use it as often as you like
There's no limit to how often you can use Head & Shoulders – it's pH balanced and gentle on hair, so you can use it every day. You don't have to stick to exactly the same Head & Shoulders shampoo, either – mix it up!
In fact, the most effective way to treat most dandruff is to use an over-the-counter shampoo, the American Academy of Dermatology (AAD) explains. You should shampoo your hair daily and swap in the anti-dandruff shampoo twice a week.How to remove dandruff naturally? ›
Lemon juice is an effective remedy that has been proven to remove dandruff naturally. As it is a rich source of citric acid, it fights dandruff from the roots of the hair follicles. The antimicrobial properties eliminate the fungus causing this dandruff!