introduction to herbalism: oil infusions

whew, it’s been a couple weeks! hello, crunchies!

welcome back to our little “introduction to herbalism” series! today we’re going to go over OIL INFUSIONS.

and here’s your friendly reminder to ALWAYS check contraindications and drug interactions when using herbs…. always. yes, they’re plants… but no, they’re not all safe all the time. 🙂


what is an oil infusion? 

an oil infusion is an infusion of herbs where the carrier oil(s) are the menstrum.

why use oil as the menstrum?

if we want to extract essential oil components, fat-soluble vitamins, carotenoids, fatty acids, tocopherols, and/or lipids, a carrier oil is our best option. knowing constituent solubility is crucial. see here if you missed our overview on that.

for example, the wound healing and skin moisturizing properties of comfrey leaf is found in allantoin, and the anti-inflammatory properties of black cumin seed oil comes from thymoquinone. both are oil-soluble only. pretty neat!


folk method / simpler’s method / solar infusion

solar infusions are just what they sound like – an oil infusion left to sit in the sun. some herbalists will say solar infusions need to only sit for 2 weeks, and some say up to 6. i personally think it depends on your carrier oil and the herbs used.

while this is the more widely-used method, i personally think it’s a tiny bit less ideal because many carrier oils go rancid in sunlight. it’s just science. the rate of how quickly they go rancid varies tremendously, but can easily be researched. try starting with looking up studies on their OSI, or oxidative stress index.

for example, argan oil should probably never be used because it’s not very shelf-stable. when kept in ideal, dark, dry conditions, argan oil rapidly loses quality after 6 months, whereas marula oil is incredibly resistant to oxidative stress and will be fine for a solar infusion.

warm bath / crockpot (not ideal but possible)

if you’re short on time and don’t need a potent infused oil, the warm bath or crockpot method is suitable.

it’s not ideal because you’re heating up the oil and herbs to a level that can potentially destroy the beneficial constituents. you’ll want to make sure you’re not using a heat sensitive oil. for example, i wouldn’t suggest you use olive oil for the crockpot method, which can begin to show markers of thermal oxidation past 22C/71F, and 33C/98F can ruin the oil completely (depending on the region the olive oil is from… so interesting!).

cold infusion

i’ve found this to be the best infusion method for me, because you don’t have to worry about oxidative stability and rancidity.

with this method you follow a solar infusion, but rather than leaving it in the sun, you leave it in a cool, dry, dark area for 6 weeks. voila.


the ratios you’ll learn will vary. some herbalists advise 1 part DRIED herb to 10 parts carrier oil. some herbalists say to fill your container up halfway with herbs and the rest with oil, leaving 1 to 2 inches of oil on top so the herbs have room to swell. no matter which you opt for (depending on what herbs you’re using), you want to make sure the herb is completely dried out so you don’t grow mold in the oil.

once your oil is infused using the method of your choice, strain, bottle in dark glass, and label your infused oil (date and contents).

how long it keeps will be up to how well you store it and what types of carrier oils you used. always store infusions away from direct sunlight, out of heat, and in a dry area.

if anything smells off or becomes murky, toss it.


you can use herbal infused oils as they are, or incorporate them into body butters, salves, hair treatments, face serums… let your creativity run wild! they’re a great way to really amp up the benefits of what you’re already DIYing.

herbal infused oils are some of my favorite things to make! what about you? have you made any, or will you now try? can’t wait to hear!



disclaimer – these statements have not been evaluated by the Food and Drug Administration. anything presented here or on this site is not intended to diagnose, treat, cure or prevent any disease. i am not a medical doctor. i will not advise on herbal remedies for ailments nor will i advise on herbal safety. your choices are your own.