Trends have seen men increasing their hygiene and grooming standards to, possibly, an all time high as of late.

Men started using moisturizers. exfoliators and and protect their skin from the dangers of sun overexposure high quality sunscreens. Still, there has been an area of grooming progression that has not evolved or enhanced for most men. This area, most commonly, is with shampoo purchasing.

Many still fall under one of two distinctions when it comes to selecting the best shampoo for men.

They, either, use the same shampoo of their bathroom mate, be it spouse, roommate, or sibling or buy whatever is on sale or convenient.

There are several, pretty simple theories for why this is the case.

For some, it’s a matter of not seeing the importance. They think, “it’s just cleaning or stripping the hair of foreign material.” If they are placing another product such as conditioner (leave in or wash out), hair clay, pomade, mousse, hair gel, etc., they believe shampoo is ultimately rendered useless other than stripping hair down to the base layer for other products. If they do see merit in quality men’s shampoo purchasing, they often get frustrated to the confusing nature of the shampoo market.

And you can’t blame them. Think about it, there’s moisturizing, hydrating, volumizing, strengthening, or smoothing.

There is shampoo for short hair, curly hair, straight hair, flat hair, and full hair.

The biggest problem here is that most men don’t understand how to match their hair type to one of these lingos and eventually just opt for the standard shampoo they have familiarity with.

On this guide, we’ll try to make things simpler for you and dive into the specifics on how to choose a good men’s shampoo based on your hair and skin type.

Best Shampoos For Men

 Woody’s Daily ShampooJack Black Shampoo and ConditionerRedken Moisturizing ShampooChristina Moss Natural ShampooDesert Essence Natural Replenishing ShampooAmerican Crew Daily Moisturizing ShampooMaple Holistics Shampoo for Dry HairKerastase Homme Anti-Oiliness ShampooDesert Essence Natural Cleansing ShampooMaple Holistics Shampoo for Oily HairNizoral A-D Anti-Dandruff ShampooHoneydew Dandruff ShampooRe:line Biotin Shampoo For Hair GrowthJack Black True Volume Thickening ShampooBrickell Men’s Strengthening Shampoo for Men
CountryUSAUSAUSAUSAUSAUSAUSAFranceUSAUSAUSA (part of J&J)USAUSAUSAUSA
Size12 fl oz / 355 ml16 fl oz / 473 ml33.8 fl oz / 1000 ml8 fl oz / 236 ml12.9 fl oz / 382 ml33.8 fl oz / 1000 ml8 fl oz / 236 ml8.5 fl oz / 250 ml8 fl oz / 236 ml8 fl oz / 236 ml4 fl oz / 120 ml8 fl oz / 236 ml8 fl oz / 236 ml16 fl oz / 473 ml8 fl oz / 236 ml
Price$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Shampoo TypeDailyShampoo and conditionerMoisturizingAll naturalAll naturalMoisturizingAll natural, moisturizingDaily treatment, anti-oilinessAll natural, anti-oilinessAll natural, anti-oilinessAnti-dandruffNatural, anti-dandruffHair loss, growth and thickeningThickeningStrengthening
Hair TypeNormalNormal and dryNormalDry, Oily, Curly or FineNormal and oilyNormal and dryNormal, dry and damagedNormal, oily and thinningNormal and oilyNormal and oilyHair with dandruffHair with dandruffThinningNormal, weak and thinning Normal, weak and thinning
Scalp TypeNormalNormal, dry and dandruff proneNormalNormal and dryNormal and dryNormal and dryNormal and dryNormal and oilyNormal and oilyNormal and oilydry and dandruff pronedry and dandruff proneAll typesAll typesAll types
Ease of Lathering4/54.5/54.5/54/54/54.5/54.5/55/54/54.5/54/54/54/54.5/54.5/5
Value for Money4/54.5/54/54.5/54/53.5/54/54.5/54/54/54/54/54/54/54/5

Before diving deeper into all things shampoo, it would be good to get a taste of our findings. So, upon doing the hard work for you, so you don’t have to, we found the following shampoos.

How to choose the best shampoo for men based on your hair and skin

Prior to making this important purchase, it is important to understand exactly what shampoo does. Shampoo serves by cleaning the hair and scalp of dirt, oil, and hair styling products like pomade, clays and hair gels.

The common misconception is that shampoo’s only function is to clean the hair. While it does clean the hair, its most important job is oriented around clean and healing the scalp. For this reason, shampoo purchase should be based on scalp condition first, then hair condition.

A common rule of thumb is to think, “purchase shampoo for the scalp, purchase conditioner for the hair.”

Why is this distinction important, one may ask?

Often these two are conflicted problems that require different treatments. For instance, many times a guys scalp is oily but the ends of his hair are dry (this is a common occurrence). If one chooses a shampoo based on the condition of the hair such as one that simply hydrates the dry hair, the scalp will become more oily and problematic.

Think about it like the face, treating the oil or dryness of the scalp (like the face) begins with proper cleansing. If one has an oily face, they wouldn’t seek heavy moisturizing face wash. They would purchase one that is oil free and doesn’t block the pores. They would look for ingredients dry the skin and standards for oily faces such as salicylic acid. Those with dry faces would look for heavy creams or milk based cleansers. Either one of these face washes for the contradicting skin type would be problematic. The same is true for scalp conditions, regardless of hair type.

Knowing Your Scalp Type

Oily Scalp

This scalp is apparent when the scalp feels (bet no one could guess this) oily or greasy. Guys with this scalp type have likely tried various shampoos without any reduction of the greasiness. They have, often, washed the hair daily or multiple times a day with very little results.

When this frustration occurs, they often go to the other extreme and take days between washing. It should be stated, the scalp, like the face has, sebaceous glands that produce the sebum or oil felt.

Like with an oily face, it is often embarrassing and enraging when the scalp, and sometimes hair as a result, feels and looks oily.

There are things that should always be done, avoided, and looked for when looking for a good shampoo for men while dealing with oily hair:

  • DON’T… purchase shampoo with a label that calls itself hydrating, moisturizing, soothing, smooth, or specifically for curly hair. Shampoos like this infuse the scalp with lots of additional moisturizer and exacerbate the problem.
  • DO… look for a shampoo that calls itself volumizing, strengthening, and balancing. These shampoos contain less ingredients dedicated to moisturize and more ingredients added to remove excess oil. Specific ingredients that work well for oily scalps are salicylic acid and sulfates.
  • For those with particularly oily scalps, look for a shampoo labeled “daily clarifying” or “rebalancing.” These serve well to train the scalp to produce much less oil as it normalizes sebum production and output.
  • Spend longer than one believes they should working the shampoo deep into the scalp. This will help the shampoo break up the oil. Be sure to rinse out twice to ensure that no shampoo remains in the hair.
  • If conditioner is applied following the shampoo, do not work the conditioner down to the scalp. Simply, place the conditioner on the top of the hair and lightly work it into the hair.

Dry Scalp

This scalp type is obvious by feeling dry, itchy, and flaking off. Many men dealing with this scalp type have trouble wearing black because of the dandruff the scalp produces. It probably goes without saying, the itchier the scalp feels the more it is scratched and the more dandruff it produces. It is of extreme importance to purchase a shampoo that does not heighten the problem.

Things to consider when buying a men’s shampoo with dry scalp are:

  • DON’T…use or purchase a shampoo that reads strengthening, fortifying, or volumizing. These will purge the scalp of its, already, limited moisture content.
  • Understand there are various levels to dry scalps. For those will minor dryness that produces little itching and no dandruff, consider buying a shampoo that promotes moisture, hydrates, smooths, or is specific to curly hair. These work as they promote the scalp to become a moisture environment by, both, moisturizing and locking in moisture. These, often, include ingredients like argan or sunflower oil.
  • If the scalp is painfully dry, itchy, and dandruff ridden, look for shampoos labelled for dry or dandruff. These usually include things like menthol and tea tree oil that deeply moisturizes. Look on the label of any current shampoo, if it contains the word sulphate in its ingredient list, odds are it is aiding in the dry scalp.

Normal Scalp

For those blessed with normal scalps and often normal hair, they have hit the jackpot because their scalp and hair is usually very easy to manage and maintain. This, scalp and hair, usually has just the right balance of oil without every feeling dry.

Since this hair is so easy to handle, it is hard to find a shampoo labelled “normal.” Look for a shampoo that gives a fairly even ratio of moisturizing and cleaning.

What about if Hair Loss is Present?

If most men are honest with themselves, they are currently dealing with or will soon deal with some form of hair loss. Two-thirds of men will experience some sort of hair loss before their 35 birthday. The main reason for this is something that can’t be avoided, genetics.

Frustratingly, no cure has been found to completely end the annoyance of hair loss. Still, there have been some innovations that work to reduce the effects of male pattern baldness.

When purchasing a shampoo for this problem, it is important that one classifies the condition.

If the hair is thinning out slowly…this is the early stage to hair loss. It is thinner than it was but one wouldn’t be considered bald.

Shampoos can help prevent continued hair loss, thicken the hair currently had, and keep the scalp healthy for a continued optimal place for hair to exist.

Ingredients in shampoos for this include things like caffeine, ketoconazole, and saw palmetto. They usually state that they are for hair recovery or hair regrowth.

If balding is taking place or already widespread, one maybe looking for something more heavy duty.

First one must come to the realization that they will never have a thick, lush head of hair again. Ingredients that have shown results for this condition are Minoxidil (which is over the counter and found in brands like Rogaine) and Finasteride (which stops DHT, the hormone at the core of male pattern baldness, found in brands like Propecia).

Here is our review of the best shampoos for men based on scalp condition and hair type.

Best Overall Shampoos For Men

Woody’s Daily Shampoo for Men

Woody's shampoo for normal hair

Made by a company that prides itself on making products without compromise by focusing on high quality ingredients that cleanse, nourish, and protect. It is for the man looking for a simple, comfortable shampoo with no frill products that smell great and get the job done.

Their products were created in collaboration with celebrity barbers and stylists. They believe their products make a man’s life slightly better with their motto, “when you’ve got Wood, it’s all good.”

This shampoo is paraben free. It has a smell that is minty with grapefruit accents that wakes one up in the morning. It is enriched with a unique blend of ProVit B5, Aloe, Ginger, and Vitamin E. These serve to sooth and protect with proteins and amino acids that build body and strength. The scalp and hair will both enjoy this shampoo.

This product comes in at a decent price that is even better when the larger container or multiple bottles are bought. Men with thick hair might experience a challenge in lathering with this shampoo as it is less foamy than some. If one is looking for a minty, old-school feeling, high quality men’s shampoo, this is the product for them.

Jack Black Double Header Shampoo Plus Conditioner

Jack Black shampoo for men with dry hair and scalp

If you have read several articles for this site, you have seen multiple reviews and recommendations for Jack Black products. This is because it is a trusted company to produce high quality skin and hair care products.

All their products are made of the finest ingredients. Many of their products are derived from time-tested natural remedies. There formulas are almost always lightweight and non-greasy. They are colorant-free, cruelty-free, sulfate-free, and tested by experts. The products have be proven to make a lot of men look and feel their best.

This product gently cleanses to remove oil and product build-up all while conditioning and soothing dry and dandruff-prone scalps. Creatine is added to increase the strength and shine of the hair. Coconut Oil works to condition and detangle. The unique addition of Organic Kelp is packed with essential minerals that nourish and thicken the hair. This product is made in the USA.

This lightly peppermint scented shampoo won a Men’s Health Award for shampoos and comes in an easy to dispense pump bottle. The price point is on the higher end but if you’re looking to buy one of the best men’s shampoos, you get what you pay for.

Regardless of claims, it has dried out the scalp of some with sensitive skin. Many report a drying out at first then healthy hair after the scalp and hair get accustomed to the shampoo. It is not an overly lathery shampoo so look elsewhere if heavy foam is desired. But that’s just a minor detail that shouldn’t drive you away from just high quality men’s shampoo.

Redken Go Clean Daily Care Moisturizing Shampoo

Redken shampoo for men

This grooming line staple has been around since 1960 but was purchased by L’Oreal in 1993. It is now available in 43 countries around the world. It has been a name that revolutionized the haircare industry with its progress and scientific products.

This is a lightweight shampoo that does a good job moisturizing. It keeps the scalp happy and hair smooth and shiny. This is great for those with slightly dry scalps. It really cleans hair and eliminates dirt and debris. It contains protein and glycerin to strengthen and brighten the hair.

This product is recommended for those with dry scalps and damaged hair. It will not work well on oilier heads. It is also a good option for those who wash their hair several times a day. It will leave the hair feeling soft through continued use.

This product does contain questionable ingredients like SLS and is not looking to be more natural.

Best Natural Shampoo for men

Christina Moss Natural Organic and 100% Natural Shampoo for All Hair Types

Christina Moss all natural shampoo for men

Christina Moss has been creating organic, preservative free hair and skin products for 16 years. The create products that do not contain toxic ingredients that cover up skin and hair. The pride themselves on revitalizing the natural beauty.

All of their products are paraben, SLS, and SLES free. They contain no PG or PG derivatives. They do not add chemical fragrances on anything harmful in anyway. They seek to put the environment first in all they do as well.

This unscented shampoo contains ingredients like coconut oil, sunflower seed oil, aloe, and shea butter. All of the ingredients are natural and high quality. It cleanses the hair without stripping or drying and soothes the scalp with pure natural and organic essential oil and ingredients. It is particular good for those with sensitive scalps as it contains nothing that could trigger flare ups.

It comes in a recycled bottle with biodegradable labels. The price is on the higher end for the size of the bottle but this is common with products with such all natural organic standards. Remember this has no scent and does not give the hair a lingering odor.

Desert Essence All Natural Organic Tea Tree Replenishing Shampoo

Desert Essence shampoo for men

Desert Essence was founded in 1978 around a simple slogan, “beauty is natural, and nature is beautiful.” They seek to bring the best nature offers to personal care regimens. They only use the best high quality products that work in harmony with the body. None of their products contain artificial colors or fragrances.

The shampoo restores moisture and balance to hair and scalp. It adds shine while limiting flaking. It deeply cleans without stripping the hair of natural oils. It contains proven ingredients like eucalyptus for medicinal properties and cooling and Tea Tree Oil for antibacterial purposes and healing for dandruff ridden scalps.

It smells like peppermint and eucalyptus. It leaves the hair relatively shiny. Some consider their hair dry after if not used with a conditioner. In fact, many people with itchy heads reported significantly less after use.

Best Men’s Dry Scalp and Hair Shampoo

American Crew Daily Moisturizing Shampoo

American Crew men's shampoo for dry hair and scalp

This company has seemed to, recently, flood stores with their products. The claim, “they make products that make the man.” Their products are usually easy to obtain and are bought at a reasonable price point.

For a shampoo that refreshes the hair and scalp, this is a good option. It contains Hydrolyzed Wheat Protein, Sage Extract, and Rice Bran Oil which all work to moisture and condition the hair and scalp without leaving it heavy feeling. It has natural extracts like Quillaja, Rosemary, and Sage for an healthy feeling head shortly after use.

This product can be used with normal hair but is mostly for dry hair. It has a nice herby scent. This product, can be easily purchased through a stylist, barber, or online. Due to its chemical components, it has make some with sensitive skin break out.

It is not highly priced but not necessarily cheap for an American Crew product. They changed the formula slightly a few years ago and many might find it less effective than it used to be.

Maple Holistics Moisturizing Shampoo for Dry & Damaged Hair with Lavender & Jojoba

Maple Holistics moisture control shampoo

Maple Holistics claims to have the goal of providing a natural, holistic range of premium products which enhance hygiene and health. They consistently deliver on that promise. Each of their products is unique, of high quality, and effective. All their products are made in the USA. They are all natural, cruelty free, and sulfate free. On all their products, they offer a 100% money-back guarantee.

If hair is unmanageable and the scalp is always itching and flaking. This is the product to consider.

It is hypoallergenic and has not added fragrances (for little scent). It does not all the often irritating moisturizing chemicals many of its competitors do. It contains ingredients like carrot oil, parsley seed, silk peptides, and almond oil that promote stronger hair and fast growth. It has jojoba and botanical keratin. The essential oils will leave the scalp with much needed moisture.

This shampoo is vitamin and antioxidant rich. It is safe for kids and adults. Some heads have not responded well to this shampoo and others have been cured in four days. The scent is a bit controversial but on the upside, it is fairly mild for this type of men’s shampoo. Price is ok for quality and the size of the bottle is decent and it can easily last you for a couple of months.

Best Men’s Shampoo for Oily Hair

Woody’s Daily Shampoo listed previously and analyzed is a great option. Let’s see a few more great options for men with oily hair.

Kerastase Homme Bain Capital Force Anti-Oiliness Shampoo

Kerastase men's shampoo for oily hair

Kerastase takes hair care seriously as it believes it provides a first glimpse into someone’s personality. It has been a luxury, progressive hair care line since 1964. They offer personalize solutions for most hair care needs. Recently, they have made huge strides to be more environmentally conscience.

This product includes Taurine. This is an amino acid that fights against the hardening of the collagen network around the base of hair, which is a major factor in premature balding. D-Biotine is a vitamin known to inhibit an enzyme responsible for hair loss that is included in this shampoo. Ingredients like Ceramide and Arginine work to protect and add depth to hair.

The pleasant scent is a hybrid of citrus and mint. This is a high end, a bit pricey product that does the job. If one doesn’t mind paying a little more for shampoo and has an oily head, this is recommended. Plus, it will provide some resistance to balding hair.

Desert Essence All Natural Organic Lemon Tea Tree Oil Cleansing Shampoo

Desert Essence shampoo for men with oily hair

Desert Essence prides itself of being a natural, socially conscious brand. It does not animal test and all of their products are 100% vegetarian. They aim to make a positive impact on people and the planet. They are considered a B-Corp Corporation, similar to Fair Trade or USDA Organic certification for non-food businesses. All of their containers are BPA free and recyclable.

The shampoo is made with Australian Tea Tree Oil and Lemon Peel Extract which gently wash away excess oil and product buildup while leaving the hairs natural moisture. Organic Maca Root Extract strengthens hair and, additionally, protects it.

This product is developed in such way so it removes excess oil and protects the scalp effectively. The scalp will feel refreshed and smooth with ingredients like jojoba seed oil that will penetrate the scalp for deep added moisture. It has the beneficial additions of tea tree oil, kelp, and shea butter as well.

This product comes with a refreshing lemon scent. It works well on oily hair and scalps. It is extremely effective for a natural shampoo. It does come with a fairly high price point but will leave the hair and scalp both smelling and feeling nice.

Maple Holistics Shampoo for Oily Hair and Oily Scalp

Maple holistics men's shampoo for greasy hair and itchy scalp

The benefits of buying a Maple Holistic product were stated above. As a reminder, they are natural, paraben free, and sulfate free. They believe in their products so much that they offer a money back guarantee.

This shampoo has an odd distinction of being great for oily hair but also working on dandruff and hair loss cases. It has lemon, cypress, and basil which reestablish a healthy head pH level and keep sebum at an appropriate production. It includes other beneficial ingredients like keratin, rosemary, and provitamin BS. These, and others, create an antioxidant rich and vitamin heavy liquid that will leave the head much healthier.

It is a great degreaser for oil hair, it prevents dandruff and stops annoying itching, and has several reports of hair growing back and looking thicker after use.

It smells ok with a citrusy scent. Some have reported wonderful results with this product while others have had less than desired results.

The price is on the higher end but it has not caused any irritations in those with sensitive skin. According to our tests as well as our research, this shampoo has worked great for men with excessively oily hair and scalp. It may be worth trying if looking for a natural shampoo that reduces oil.

Best Dandruff Shampoo for men

Nizoral A-D Anti-Dandruff Shampoo

Nizoral A-D Anti-Dandruff Shampoo

This is a product that has long required a prescription but now Nizoral is available over the counter.

Understand how dandruff happens. P. ovale is a fungus that exists on every human head. Things like climate, heredity, diet, stress, etc impact how the body reacts to it. For those with dandruff, the natural process of scalp-cell renewal is sped up when fighting P. ovale, causing dead cells to fall off faster. Nizoral works to kill off this fungus.

It contains an ingredient called ketoconazole which binds to the hair and keeps it working. For this reason, other shampoo or days off can be routine while using. It is recommended to onl use this shampoo 2 times a week with this product.

This shampoo works really well. It doesn’t smell overly chemically like many others specific to dandruff issues. It lathers really well.

It has worked wonders for those that found relief with no other shampoos. A warning must be said, try to avoid getting this on the face as it has caused peeling and irritation if a lot falls on the face.

One thing to note is that it does contain some questionable ingredients for those looking for natural products. But sometimes dandruff can’t be fixed with all natural solutions. Bottle is smaller than your regular shampoo and price is reasonable for the amount needed and results.

Honeydew Dandruff Shampoo with Tea Tree Oil

Honeydew dandruff shampoo for men

Honeydew specializes in organic, natural, healthcare products. They make products for the entire body from skin to hair. They offer a 100% money back, no questions asked refund policy.

This product includes tea tree oil from Australia, 100% pure jojoba, and rosemary. It goes deep into the scalp to refresh and create a healthy head environment for hair growth.

It is paraben free, sulfate free, and safe for all hair. The tea tree oil gives it a pleasant scent and fights off dandruff with its anti-fungal properties. It leaves the hair clean and quickly reduces the flakes.

Some do not like the smell of tea tree oil and claim this shampoo smells like pinesol, which is fair. It is more natural but not really as effective as other dandruff shampoos mentioned. It would be good for light cases of dandruff but not recommended for those with more severe cases. Overall, you get a good value for the money as it’s priced fairly decently.

Best Hair Loss Shampoo for men

Paisle Botanics Biotin Shampoo for Hair Growth

Re Line hair growth shampoo for men with biotin

This company sought out to make a hair growth shampoo that was sulfate free and paraben free and did just that. This shampoo is safe for all hair, colored or not. It was created with ingredients found in nature. If one doesn’t like this product there is a 100% money back guarantee.

Its formula is a unique blend of Biotin saw palmetto and rosemary oil. These work together to build body in fine thinning hair and stimulate the scalp to encourage new growth. Aloe Vera and coconut oil hydrate the hair and scalp for Vitamin B and E absorption for added hair growth benefits.

This product has a nice botanical scent unlike many hair growth shampoos. It works with all hair types. It does give the hair a fuller look and reduces the rate it falls out in most (some have not seen the same positive results). It is a safer product for those looking for less chemicals that worse.

Jack Black True Volume Thickening Shampoo

Jack Black Thickening shampoo for men with hair loss

Jack Black continues to be a trusted player in hair and skin care and this product is not exception. It serves as a daily shampoo that thickens the thinning hair.

Creatine is included as it penetrates hair shaft and strengths the hair while adding volume. Wheat Protein bulks up the thin hair and white lupine reheals the scalp for a good regrowth platform. Tea tree oil and sage leaf oil fight off fungus and reduces itching. Lavender oil makes it smell nicely while providing anti-inflammatory properties. Hair is left moisturized and hydrated with sunflower seed oil. Biotin is, also, present to strengthen and repair.

The product is vegan and cruelty-free. It is paraben, sulfate, alcohol, and synthetic fragrance free. It is dermatologist tested. Although the smell is not great to some, others may love it.

The bottle leaves a little to be desired for application. It helps with dandruff and noticeably thickens the hair. It comes in a decent sized bottle with a fairly high price but it is another Jack Black product that delivers.

Brickell Men’s Daily Strengthening Shampoo for Men

Brickell thickening shampoo for men with hair loss

Last but certainly not least is the daily thickening shampoo by Brickell Men’s Products.

We’ve tried quite a few products by Brickell already, including a few different shampoos and they all deliver excellent performance while coming with premium ingredients.

The particular shampoo is meant to be used by men who have weak and thinning hair.

More specifically, it contains 97% natural ingredients among which hydrolized proten and amino acids that make your hair healthier and stronger. Hydrolyzed protein is used for strengthening the hair structure which in turn, helps with thickening the hair strand together with Vitamin E that stimulates the scalp for minimizing hair loss. At the same time, amino acids increase the volume of your hair follicles.

Although the shampoo might be a bit hard on your scalp, many users have seen great results in terms of hair thickening in a matter of two to three weeks. I’ve used it myself as well but I’ve got pretty strong hair and I didn’t see much of a difference but there’s already strong customer base that supports the claim that it makes the hair healthier and stronger.

It builds lather quickly on wet hair and the scent is fairly pleasant.

Price wise, it’s going to cost you almost the same as other premium natural shampoos that come in a 8 oz /236 ml bottle. A little goes a long way and it’s going to last you a few good months.

Closing thoughts

Shampoo choices matter more than most people believe. Providing proper hair care has a huge impact on overall health and self-confidence. When one is not worrying about dandruff or dry hair, when they aren’t worried about their hair looking oily and dirty, the day, simply, improves.

While one can cover up some of these problems with other hair care products, nothing fixes the source of the problem (the scalp) more effectively than the shampoo because it gets to the root of the problem (both figuratively and literally).