Scalp serum before or after leave-in conditioner? The full order

In most routines, a scalp serum goes on before leave-in conditioner: serum onto the bare scalp along your parts, massaged in and given a few minutes to settle, then leave-in on the mid-lengths and ends. Heat protectant follows on the lengths, then the dryer, then root lift, and dry shampoo only ever goes on top of a serum that has fully dried.

The reason is placement, not chemistry. A scalp serum is made for skin, and everything else on this list is made for the hair fibre. Get the scalp product down while the scalp is still clear, then build the style on the lengths. This guide goes through each product in turn, what happens when the order slips, and three sample routines you can copy. For the general rule on oils and serums, hair oil or serum: which one goes on before the other has the full order; here the focus is the styling products that crowd the roots.

The short version

1. Scalp serum, then leave-in. Serum on the scalp, leave-in from the mid-lengths down.
2. Give the serum a few minutes. Let it settle before anything else goes near the roots.
3. Heat protectant on the lengths, after the leave-in and before any heat.
4. Blow-dry after the serum, on a low or medium setting, with the dryer moving.
5. Root lift and mousse go on the hair at the base, sparingly, once the serum has dried.
6. Dry shampoo goes on top, never underneath, and only on a dry scalp.
7. Oil and hairspray finish the style, on the ends and the outside of the hair.

Scalp serum before or after leave-in conditioner: why before works

A leave-in conditioner is a conditioner that stays in. Conditioners deposit on the fibre to smooth the cuticle and cut friction between strands, and a review of hair cosmetics is direct about where they belong: the conditioner should be applied on the hair length, avoiding the scalp.¹ The American Academy of Dermatology gives similar advice for fine or straight hair, which is to put conditioner on the ends.²

A scalp serum is the opposite case. It is meant to reach skin, which means the roots need to be clear when it goes on. Put the serum down to start and both products land where they were designed to go. Reverse it and two things can happen. The serum has to get through conditioner at the roots, and conditioner ends up on the scalp, where the same review notes that leave-on products on straight hair can give an oily look and dull the hair.¹

There is also a practical point about hands. Slippery, conditioner-coated fingers make poor parts. Doing the serum while your hands are clean keeps the parting neat and the dose where you meant it.

If your leave-in goes on in the shower

Many curly and coily routines put leave-in or styler on soaking wet hair in the shower, and nobody wants to stop that to make parts in dripping hair. In that case, keep the leave-in well down the lengths, finish your styling, and apply the scalp serum later on a dry scalp by parting with the tail of a comb. The order on the head is still serum on skin, leave-in on hair. It is only the order in time that changes.

Spray leave-ins

Sprays drift. A leave-in mist aimed at the lengths will settle on the crown and the part line if you spray from above. Hold the bottle level with the mid-lengths, spray sideways into the hair, and cover the part with your other hand if you need to.

Where heat protectant goes

Heat protectant has one fixed rule: it has to be on the hair before the heat. The AAD advises limiting blow-drying and hot tools, keeping them to low or medium heat, and using a product that protects hair from heat.² The review of hair cosmetics describes the protector used for a dryer or flat iron as a silicone that spreads heat along the surface of the fibre.¹ In one laboratory study, hair pretreated with selected polymers broke significantly less after hot flat ironing at temperatures over 200 °C; the work came from a company that supplies such polymers, so read it as a lab finding, not a verdict.³

So the protectant goes on the lengths, after the leave-in and after the scalp serum. Two things to check on your own bottles. Some leave-ins are also heat protectants, in which case one product covers both steps. And a silicone protectant is a coating, which is what you want on the fibre and not what you want on a scalp you have just treated. Start it a hand's width from the roots and work down.

Scalp serum before or after blow-drying

On a wash day, the serum goes on before the dryer. We cover the wet, damp and dry options in scalp serum before or after the shower; what matters here is the sequence with everything else. Towel-dry, apply the serum, give it a few minutes, then add leave-in and protectant to the lengths and start drying.

How you dry matters as much as when. A study in the Annals of Dermatology found that a hair dryer used at 15 cm with continuous motion caused less damage than letting hair dry naturally, while closer distances meant higher temperatures and more surface damage.⁴ Keep the nozzle moving, keep it off the scalp, and point the airflow down the lengths.

If you style before applying the serum instead, part the dry hair with a comb, apply along the parts, and lift the roots back with your fingers once it has dried. That is the better order on days when you want the blow-dry done before you leave the bathroom.

Mousse, root lift sprays and volumizers

These are the products that actually compete with a scalp serum for space, because they are designed to go at the roots. The way to share that space is to let each one do its own job on its own surface. Apply the serum, let it dry down, then put the volumizer on the hair at the base, a few centimetres out from the skin, rather than rubbing it into the scalp.

Use less than you think. Styling polymers, the film formers in many mousses, gels and sprays, build up on the hair shaft with continuous use and can make hair look rough and dull and feel harsh, according to a review of shampoos and conditioners.⁵ For people with seborrheic dermatitis, the AAD's self-care advice is to apply hair spray, gel or pomade sparingly.⁶ A weekly shampoo that properly clears the roots stops any of it piling up.

The order at a glance

Drop the ones you do not use; the rest keep their order.

Product	Where it goes	Hair	Before or after the scalp serum	Why
Rinse-out conditioner	Lengths and ends	Wet	Before	Rinsed out in the shower, so the scalp is clear again
Leave-in conditioner	Mid-lengths and ends	Damp	After	Made for the fibre; keeps conditioner off the scalp
Heat protectant	Lengths	Damp or dry, per its directions	After	Must be on the hair before heat, but not on the scalp
Blow-dry	All, airflow down the lengths	Damp to dry	After	Serum settles before heat; lift comes at this stage
Mousse or root lift spray	Hair at the base	Damp or dry	After, once the serum has dried	Polymers are for hair, not skin, and build up if overused
Hair oil or smoothing serum	Ends	Dry	After	A film goes last, well away from the roots
Dry shampoo	Roots	Dry	After, once fully dry	Powder on a wet serum turns to paste
Hairspray	The outside of the style	Dry	After	Holds the finished shape

Scalp serum and dry shampoo

Dry shampoo is the one product that can undo a scalp serum if the order slips. The AAD's dermatologists explain that dry shampoo contains particles that absorb oil but does not clean the hair, and that it should not replace regular shampooing. Start on the scalp, apply a little at a time only where you need it, then brush or comb it out after the time on the directions. They agree you should wash after one or two dry shampoos, and they note that using dry shampoo alone may lead to seborrheic dermatitis, an itchy, scaly scalp rash.⁷

Three rules follow for a scalp serum:

• Serum underneath, dry shampoo on top. Powder on a scalp still damp with serum clumps into paste and sits on the skin.
• Fully dry means fully dry. Give a water-based serum time to dry down, or put the dry shampoo on before bed and the serum on the next scalp that has been washed.
• Do not stack days. Serum plus dry shampoo every day for a week is a lot of material on one patch of skin. Wash after one or two dry shampoo days, then start clean.

Dry shampoo as a volume product

Plenty of people with fine hair use dry shampoo on clean hair purely for grip and lift. That is fine, and the same order applies: it is a finishing product, so it goes on after the serum has dried, sprayed at the hair near the base rather than packed onto the skin.

Oil, smoothing serum and hairspray

Finishing products go last because they sit on the outside of everything else. A drop of oil or a silicone smoothing serum goes on the ends, warmed between the palms, never up at the roots. Hairspray goes on the outside of the finished style. Neither needs to touch the scalp, and on fine hair either one at the roots will flatten the lift you just built. The difference between a scalp serum and a smoothing serum is covered in scalp serum vs hair serum.

Three sample routines

Wash day with a blow-dry

1. Shampoo on the scalp, conditioner on the lengths, rinse.
2. Wrap the hair in a towel; the AAD advises against rubbing it dry.²
3. Scalp serum along your parts, massaged in, a few minutes to settle.
4. Leave-in on the mid-lengths and ends.
5. Heat protectant on the lengths.
6. Blow-dry on low or medium, dryer moving, lifting at the roots with a brush.
7. A drop of oil on the ends if they need it.

Wash day, air-dried

1. Shampoo, conditioner, rinse, towel.
2. Scalp serum on the damp scalp, massaged in.
3. Leave-in or styling cream on the lengths, scrunched or smoothed.
4. Leave it alone to dry. No heat, so no protectant.

Second day, no wash

1. Part the dry hair and look at the scalp. If yesterday's products are still there, wash instead.
2. If the scalp is clear and the serum's directions allow it, apply along the parts and let it dry.
3. Dry shampoo on top, only where the roots need it, then brush it through.
4. Hairspray or a touch of oil on the ends to finish.

For the technique of applying the serum itself, read how to apply a scalp serum, step by step. If the roots still end up heavy, why a scalp serum can make hair greasy goes through the usual causes, and layering too many root products is one of them.

A note on new products

Every new product in the routine is a new thing on the skin. Patch test it before it goes near the scalp: the AAD suggests applying it twice a day for seven to ten days to a quarter-sized spot on the inner arm or the bend of the elbow.⁸ If the scalp itches, stings or reddens after you start something, stop, wash it off gently and do not use it again. When several new products start in the same week, you will not know which one caused it, so add them one at a time.

Everything in this guide is about how hair looks, feels and styles, which is what a cosmetic does. In US law, a product intended to restore hair growth is a drug, not a cosmetic,⁹ so for hair loss, the right person to see is a dermatologist.

Common questions

Do you put scalp serum on before or after leave-in conditioner?

Before, in most routines. The serum goes on the bare scalp and is massaged in, then the leave-in goes on the mid-lengths and ends. If your leave-in goes on in the shower, keep it well below the roots and apply the serum later on a dry scalp by parting the hair with a comb.

Should I apply scalp serum before or after blow-drying?

Either works. Before is simpler on a wash day: apply to a towel-dried scalp, let it settle for a few minutes, then dry on a low or medium setting with the dryer moving. After suits a finished blow-dry, as long as you part the hair with a comb and lift the roots again once the serum has dried.

Does heat protectant go on before or after scalp serum?

After. The scalp serum goes on the scalp, the heat protectant goes on the lengths, and both happen before any heat. Keep a silicone protectant a hand's width away from the roots, because a coating made for the fibre has no job to do on the scalp.

Can I use dry shampoo after scalp serum?

Yes, once the serum is completely dry. Dry shampoo on a damp serum clumps. Apply a little only where the roots need it and brush it through. Dermatologists suggest washing after one or two dry shampoo days, so the next serum goes onto a clean scalp.

Can I use mousse with a scalp serum?

Yes. Apply the serum, let it dry, then put a small amount of mousse on the hair at the base rather than on the skin. Styling polymers build up on the hair with continuous use, so keep the amount small and wash thoroughly once a week.

Can I use scalp serum and leave-in conditioner together every day?

Yes, because they go on different parts of the head. Use the serum's usual dose on the scalp and a small amount of leave-in on the lengths. If the roots start to look heavy, check that the leave-in is not creeping up to the part, and cut the leave-in before the serum.

Ours

Both of our serums are water-based, with no oils, no silicones and no added fragrance, so they dry down on the scalp and leave the lengths to your styling products. Max Density is the morning serum: a few drops on a clean scalp, massaged for one to two minutes, and left on at least one to two hours before washing, which makes it step three of a wash-day routine above. Max Growth is the evening serum, with nothing to rinse out, so it goes on before bed, after the day's styling products have been brushed out.

Both contain rosemary extract, and the European Medicines Agency notes that the safety of rosemary preparations in pregnancy and lactation has not been established.¹⁰ Max Growth also contains saw palmetto, which the NCCIH says may be unsafe during pregnancy or while breastfeeding.¹¹ If you are pregnant or breastfeeding, talk to your doctor before using either.

Eloura products are cosmetics. They are not intended to diagnose, treat, cure or prevent any condition. This article is general information about hair care and is not medical advice.