Hair Oil Guide: Everything You Need to Know
My grandmother oiled her hair every single week of her life. She had the thickest, healthiest hair of anyone I knew well into her seventies. For years, I thought hair oiling was old-fashioned—until I realized she was onto something the rest of us forgot.
Why Hair Oiling Actually Works
Hair oiling isn't just about shine (though that's a nice bonus). It's about protecting and strengthening your hair at a structural level.
Your hair is made of a protein called keratin, arranged in layers like roof shingles. The outermost layer—the cuticle—protects the inner cortex. When the cuticle is damaged (from heat, chemicals, or friction), moisture escapes and hair becomes dry, brittle, and prone to breakage.
Oils help in two ways. Some oils (called penetrating oils) can actually enter the hair shaft and reduce protein loss during washing. Others (sealing oils) coat the cuticle, locking in moisture and smoothing down those "shingles" for a sleeker appearance.
The best oils for penetrating the hair shaft are coconut, olive, and avocado oil—they have molecular structures small enough to get inside. Heavier oils like castor and argan work better as sealants.
Understanding Different Types of Hair Oils
Not all hair oils are the same. Understanding the categories helps you choose wisely.
Carrier Oils
These are pressed from seeds, nuts, or fruits and can be used directly on hair. Examples include coconut oil, jojoba oil, argan oil, olive oil, and sweet almond oil. They moisturize, protect, and often have additional benefits depending on their fatty acid profile.
Essential Oils
Concentrated plant extracts that must be diluted before use. Rosemary, peppermint, lavender, and tea tree are popular for hair. They're used for specific benefits like promoting growth or treating scalp issues, not general moisturizing.
Blended Hair Oils
Commercial products that combine multiple oils, often with added fragrances or silicones. Convenient but often pricier and may contain ingredients that cause buildup. Read labels carefully.
Which Oil Is Best for Your Hair Type?
The "best" hair oil depends entirely on your specific hair. Here's a starting point.
Fine or Thin Hair
Lightweight oils that won't weigh hair down: jojoba, grapeseed, argan. Apply sparingly to ends only. Avoid heavy oils like castor that can make fine hair look greasy and limp.
Thick or Coarse Hair
Richer oils that provide substantial moisture: coconut, olive, avocado. You can use these more liberally from scalp to ends. Your hair can handle the weight and benefits from the extra hydration.
Curly or Coily Hair
Penetrating oils for moisture plus sealing oils to lock it in: coconut or olive for moisture, castor or shea butter blends for sealing. The LOC/LCO method (liquid, oil, cream or liquid, cream, oil) works wonders for curl definition.
Color-Treated Hair
Gentle, protective oils: argan, jojoba, macadamia. These help maintain color vibrancy and repair chemical damage without stripping. Avoid oils that might alter color, like olive oil on blonde hair.
Oily Scalp, Dry Ends
Focus lightweight oils on ends only: jojoba or grapeseed on mid-lengths and ends. Skip the scalp entirely or use a clarifying treatment occasionally instead of oil.
When trying a new oil, do a strand test first. Apply to a small section of hair for a week and assess before committing to your whole head. Some hair types react unexpectedly to certain oils.
How to Oil Your Hair Properly
Technique matters almost as much as the oil itself. Here's how to get the most benefit.
Pre-Shampoo Treatment
Apply oil to dry hair 30 minutes to overnight before washing. This protects hair from the drying effects of shampoo and reduces protein loss. Cover with a shower cap or silk bonnet if leaving overnight.
Post-Wash Treatment
Apply a few drops to damp or dry hair after styling. Focus on ends and any areas prone to frizz. Use sparingly—you can always add more but can't take away without rewashing.
Scalp Massage
Warm a small amount of oil in your hands, then massage into your scalp using circular motions for 5-10 minutes. This stimulates blood flow to hair follicles and distributes the oil evenly. Great for promoting growth and relaxation.
Hot Oil Treatment
Warm your oil (never microwave—use a bowl of hot water). Apply to hair, cover with a plastic cap, then wrap with a warm towel. The heat helps the oil penetrate deeper. Leave for 30 minutes to an hour before washing.
How Often Should You Oil Your Hair?
There's no universal answer, but here are guidelines based on hair type.
For dry or damaged hair, 2-3 times per week with a pre-shampoo treatment plus daily touch-ups on ends.
For normal hair, 1-2 times per week as a pre-shampoo or weekly hot oil treatment.
For oily hair, once a week or less, focusing only on ends. Some people with oily scalps skip hair oiling entirely and that's fine too.
Common Hair Oiling Mistakes
I've made every mistake on this list. Learn from my greasy, product-laden past.
Using too much oil. Start with less than you think you need. You can always add more, but removing excess without washing is nearly impossible.
Oiling dirty hair. Always start with relatively clean hair. Oil on top of product buildup just creates more buildup.
Sleeping without protection. Oil will transfer to your pillowcase, potentially clogging pores on your face and ruining your bedding. Use a silk or satin bonnet, or at minimum a towel on your pillow.
Not washing out properly. Heavy oils need thorough shampooing. One wash often isn't enough—sometimes you need two or a clarifying shampoo.
The Bottom Line
Hair oiling is one of the oldest beauty practices for good reason—it works. The key is matching the right oil to your hair type, using the right amount, and applying it correctly.
Start simple. Pick one oil that matches your hair type, try it for a month, and see how your hair responds. You can always expand your collection later. My grandmother kept it simple with just coconut oil, and look how that turned out.
After years of heat damage and chemical treatments left my 4A curls lifeless, I dedicated myself to learning everything about natural hair care. Now I help women embrace their natural texture with science-backed tips and real-world advice. When I'm not researching the latest in hair science, you'll find me mixing DIY hair masks in my kitchen.