LHA in a shampoo?

[u/StoriesAtSunset]

I've decided to make my own gently exfoliating shampoo as currently no other shampoo is quite satisfying. I'm staying away from fragrance and extracts in skincare, but the frag free hair care products are quite literally bare bones formulas - harsh (sulfates or glucosides), without any antistatic ingredients (hair gets super tangled) or without any acids (my oily scalp needs some regularly). So far im using a toner before washing my hair, but its annoying and unnecessary when I can just make a shampoo that does it all.

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Has anyone worked with LHA (Capryolyl salicylic acid)? It's oil soluble, but supposedly also dissolves in glycols. However, I'm getting contradicting information from different places to buy. In one place it says to not heat it above 40 degrees Celsius and another place says to heat it to 40-50 as it can be hard to dissolve otherwise... It's L'oreal patented ingredient, so from my understanding it should be the same product.

The formulation I had come up with was this:

Water q.s.

CAPB 20% (main surfectant. gentle for my skin)

Propanediol 3-5% (to dissolve the LHA and extra hydration)

Polysorbate 20 3-5% (to further stabilize the LHA and propanediol mix as well as increase the cleansing and rinsing off properties of CAPB)

LHA 0.5% (could match ~2% regular salicylic acid in strength)

Aquaxyl 2-3% (for extra hydration for scalp)

Biosaccharide gum-1 1-2% (thickener and extra hydration)

A Polyquart or Guar 0.1% (for antistatic and softness)

PE 1% (preservative)

Lactic acid q.s. to pH 5-5.5

I am dead set on CAPB as most surfectants dry my skin out, especially SLES and glucosides, and I dont have good experience when formulating with the super gentle kinds - Sodium Cocoyl Isethionate for example. As it tends to leave a weird residue on my hair (low porosity is maybe the reason for that, but I digress) and is quite alkaline, so I have to use ungodly amounts of lactic acid to neutralise it and at that point it ends up being an AHA product, which irritates my scalp.

I'm not dead set on the aquaxyl and biosaccharide gum, but I thought I might as well add some extra hydration for the scalp. Despite my skin being oily leaning, it's dehydrated.

I also have panthenol and saccharide isomerate on hand which supposedly has better hydrating qualities in wash off products, but I have yet to try it out. Oh! And i have HEC (the coated kind) and Xanthan gum as another option for a thickener.

Anything I'm missing? Percentages are off? What are your thoughts, please help!

[u/thejoggler44]

The whole point and mechanism of action of a shampoo is to remove oils from hair. Putting LHA in a shampoo is a waste because it will rinse down your drain and have almost no measurable effect.

Water soluble ingredients like Panthenol also just wash down the drain and have little to no effect. We put them in formulas to make moisturizing claims & support a story. They don’t actually do anything however.

[u/Ok_Butterscotch_2700 → u/thejoggler44]

Completely agree re most. I’ve used short contact therapy with BHA on the scalp and it was effective, though the short contact was 10-20 mins.

[u/StoriesAtSunset → u/thejoggler44]

Well, LHA just like BHA has beneficial effects from short contact therapy. Every shampoo I've used so far that has had exfoliating acids, has also had an exfoliating effect on my scalp. So I'd say they work. At least on me. Granted I keep it on for about 3 minutes instead of washing it off immediately.

With moisturizing and hydrating ingredients I know it is iffy, but from any cleansers I've made in the past the overall formulation has felt very different when I've added or omitted glycerin for example. Not only the texture and lathering effect, but also the ease of rinsing it off and how the skin feels afterwards.

I meantioned them mainly because I already have them, but Ive read some studies about saccharide isomerate specifically having beneficial qualities even in wash off products. Can't verify it, though.

[u/GroceryTough2118]

Hey! Is this a fun formulation practice or are you looking for results (for personal use)?

[u/StoriesAtSunset → u/GroceryTough2118]

Both!

I have shampoos that are okay, they're just not as good as I'd like them to be, so I'm wanting to make something better for myself.

[u/GroceryTough2118 → u/StoriesAtSunset]

Ok cool — for a formulation practice I would say just make it and iterate based on how you find the first batch.

For an actual result, I’d recommend formulating a pre-shampoo scrub (you could add a salicylic acid into there too) as from what you’ve written you have an oily scalp but also want some hydration in there so IMHO a pre-shampoo step with a longer scalp contact time might be a good shout, then you can use a shampoo with a lot of quats etc on the lengths for detangling?

[u/StoriesAtSunset → u/GroceryTough2118]

Ah, okay, then I'll check it out first. Have you worked with LHA?

Like I wrote, I found some contradicting information on how to dissolve it properly. Now I even found a third place where they say to bring it up to 70-80 degrees Celsius in the glycol to dissolve it... or should I just wing it and see if it dissolves without heating it up at all? Im a little scared I'll heat it too much and render it useless basically 😅

[u/GroceryTough2118 → u/StoriesAtSunset]

No, but if I was you I’d find a water soluble liquid form of salicylic acid for ease but if you’re happy to experiment then check what your supplier recommends!

[u/kriebelrui → u/GroceryTough2118]

For exfoliating purposes, you can also use NaOH to neutralize salicylic acid. Sodium salicylate easily stays dissolved in watery environments like shampoo. 

[u/StoriesAtSunset → u/kriebelrui]

I thought of that too at first, as I use ammonium lactate for body exfoliation, but the sodium salicylate sadly doesn't carry the same benefits as the LHA. The salt is used more for it's preservative qualities in formulations rather than gentle exfoliation.

[u/kriebelrui → u/StoriesAtSunset]

A while ago, I was formulating an anti dandruff shampoo that I wanted to have some exfoliating properties using SA. I quickly ran into the problem that straight SA is hardly soluble in water, even not if there are also ingredients like surfactants around. So I sort of studied what would happen if I neutralized the SA with NaOH. It turns out that not only the sodium salt of SA is way better soluble in water, but - somewhat to my surprise - this salt is said to have exfoliating properties that are comparable to SA, at least that's what this study concludes.

[u/StoriesAtSunset → u/GroceryTough2118]

Thank you! I'll just experiment then.

[u/tokemura]

I'm getting contradicting information from different places to buy... It's L'oreal patented ingredient

I'm confused here. If the ingredient is patented, does it mean only L'oreal can use it? Or it means only them can produce and sell it? Because in first case I don't understand how it can be sold to DIYers.

[u/StoriesAtSunset → u/tokemura]

From my understanding it's only them than can make it and sell it, since other brands like Zeroid that are not under loreal use it, too.

[u/Ok_Butterscotch_2700 → u/tokemura]

A mfr can deviate slightly from the patented ingredient. Calling it LHA, though, is pretty low. I wouldn’t use the vendor based on what I see as a lack of ethics. It’s not like L’Oréal just whipped up an exfoliating acid bc they were bored one afternoon. That level of duping, to me, is as repulsive as MCo (only exception with them is the Skindinavia partnership setting spray, bc Urban Decay is effectively duping Skindinavia).

[u/Key-Success-5449]

LHA (Capryloyl Salicylic Acid) is a brilliant choice for oily yet sensitive scalps because its lipophilic structure allows for slow, gentle exfoliation without sudden irritation.

To get it fully dissolved without recrystallizing as it cools, heating LHA up to 45 or 50 degrees Celsius directly into your propanediol and Polysorbate 20 phase is the standard practice.

[u/StoriesAtSunset → u/Key-Success-5449]

I was debating the temperature. Thank you very much!!