Today we’re whipping up a simple, seven-ingredient Featherweight Leave-In Hair Conditioner that is brilliant for adding moisture and shine to hair that’s not very tolerant of oils. I’ve been using variations on this conditioner for over a year now, and I love how it softens and smooths my hair without leaving it looking stringy or dirty. I particularly love it during dry winter months (our dew point is usually well below 0°C… last week it was below -30°C!) and if I’ve been using hot tools on my hair. If you don’t have all seven ingredients you can pare down the formulation to just use four or five, too!
Want to watch this project instead of reading it?
This Featherweight Leave-In Hair Conditioner was born out of my initial “get-to-know-you” experiments with behentrimonium chloride (BTMC) back in 2018. Behentrimonium chloride (BTMC) is similar to behentrimonium methosulfate (BTMS) in that they are both fatty, cationic, conditioning ingredients. I’ve shared a lot of formulations using BTMS over the years, but this is the first one using BTMC. I brought home a bag of behentrimonium chloride (BTMC) from one of my trips to the US in 2018 (when I travel to the US I’ll have orders from American suppliers shipped to my hotel or Airbnb ahead of time so I can try new ingredients that aren’t available in Canada without paying international shipping and duties, which can easily double the cost of an order). The “use” instructions from Making Cosmetics were “Use level 0.5-3 %, add pellets to warm water or oil (85°C) to melt.” Simple enough, no? I tried 1% behentrimonium chloride (BTMC) in hot water and found that while that worked nicely initially, it wasn’t very stable—the behentrimonium chloride (BTMC) would separate out pretty quickly.
To stabilize the behentrimonium chloride (BTMC), I incorporated some cetearyl alcohol, taking inspiration from BTMS-25, which is 25% behentrimonium methosulfate and 75% cetearyl alcohol. That worked really well, creating a surprisingly thick, creamy product that imparted beautiful ultra-light conditioning goodness to my fine hair without weighing it down. The behentrimonium chloride (BTMC) emulsifies the cetearyl alcohol into the water, and the cetearyl alcohol adds viscosity and stability along with a bit of richness.
I used that simple concoction (plus preservative and some fragrance) for the better part of a year before realizing I should really share it with you guys! I amped it up a bit, including some panthenol to reduce breakage and add shine, and some hydrolyzed rice protein to volumize and moisturize the hair, but the overall formulation is still fairly simple with just seven ingredients (and you can leave out the amp-up add-ons if you want).
Much like in the Featherweight Hair Oil formulation I shared earlier this month, the key to the lightness of this formulation is the dilution of heavier ingredients (oils, conditioners, etc.) with something that won’t weigh down the hair. The hair oil formulation dilutes heavier oils with ultra-light liquids like cyclomethicone and isododecane. In this formulation, heavier behentrimonium chloride (BTMC) and cetearyl alcohol are diluted with water. If you have ingredients like cyclomethicone or isododecane, an emulsified product like this is a good alternative—and this one has the added benefit of containing some conditioning goodness from the behentrimonium chloride (BTMC)!
The making part is easy-peasy. We’re adding just-boiled water to our heated phase, blending the ever-living daylights out of that, and then incorporating our cool down phase. That’s it! The end product works beautifully in a bottle with a treatment pump so you can easily dispense a small amount of conditioner for each use. A treatment pump is much smaller than a standard lotion pump—I’d say it dispenses about 1/4 the amount of product or less in any given pump, making it great for products we use in smaller amounts.
Want to watch this project instead of reading it?
Featherweight Leave-In Hair Conditioner
56.4g | 94% distilled water
Weigh the behentrimonium chloride (BTMC), cetearyl alcohol, and panthenol into a small beaker.
Boil some distilled water in another beaker (I put approximately 80mL of water in the microwave for about 2 minutes until it was at a rolling boil).
Once the water is at a rolling boil, quickly weigh the required amount into the beaker with the rest of the heated phase, and then blend thoroughly. The cetearyl alcohol and panthenol will melt/dissolve very quickly, but I find the behentrimonium chloride (BTMC) needs some thorough blending to melt and incorporate. To ensure stability please make sure you blend the mixture very thoroughly; I recommend using something like a hand-held mini mixer or immersion blender (though you’d likely want to scale the formula up to 100g [3.5oz] if you use an immersion blender).
When the conditioner is cool it’s time to incorporate our cool down ingredients. Because cool down ingredients are typically present at very low amounts you’ll need to use an accurate scale—preferably one accurate to 0.01g. As these more accurate scales tend to have fairly low (100–200g) maximum weights you won’t be able to put the entire batch of conditioner on that scale without blowing it out. So—grab a smaller dish. Add a scoop or two of conditioner, and then weigh the cool down ingredients into that, using the more accurate scale. Stir to thoroughly incorporate, and then stir all of that back into the parent batch of conditioner. Doing it this way minimizes the amount of cool down ingredients lost to the secondary container.
That’s it! Transfer the conditioner to a container and you’re done. I used a 60mL (2 fl oz) bottle with a treatment-pump top.
To use, work a small amount of conditioner (I’d start with a nickel-sized amount) through the hair as needed.
Because this conditioner contains water, you must include a broad-spectrum preservative to ward off microbial growth. This is non-optional. Even with a preservative, this project may eventually spoil as our kitchens are not sterile laboratories, so in the event you notice any change in colour, scent, or texture, chuck it out and make a fresh batch.
As always, be aware that making substitutions will change the final product. While these swaps won’t break the recipe, you will get a different final product than I did.
- As I’ve provided this recipe in percentages as well as grams you can easily calculate it to any size using a simple spreadsheet as I’ve explained in this post. As written in grams this recipe will make 60g (1.06oz).
- To learn more about the ingredients used in this recipe, including why they’re included and what you can substitute them with, please visit the Humblebee & Me Encyclopedia. It doesn’t have everything in it yet, but there’s lots of good information there! If I have not given a specific substitution suggestion in this list please look up the ingredient in the encyclopedia before asking.
- I don’t recommend swapping out the behentrimonium chloride (BTMC); if you do, you’ll need to re-test the formulation to ensure it’s stable. I would probably try 2% BTMS-50 and 1–2% cetearyl alcohol as a starting point.
- You could try a blend of cetyl alcohol and stearic acid as an alternative for the cetearyl alcohol, but you will need to re-evaluate the product for stability if you do that.
- Please refer to the encyclopedia for alternatives for panthenol.
- You could use a different hydrolyzed protein (quinoa, silk, baobab, etc.) in place of hydrolyzed rice protein.
- If you’d like to really simplify this conditioner you could drop the panthenol and hydrolyzed protein (replacing them with more distilled water). You could also drop the fragrance/essential oil in the same manner.
- You could use a hydrosol instead of the water rather than including a frangrance/essential oil (or in addition to).
- If you’re like to use a different preservative, please review this page.