Whether it's coconut oil, almond oil, olive oil, or lemon oil - with an explosion of interest in oils from culinary backgrounds, it can sometimes feel like modern hair care will have you just as prepared to make a salad as you are to care for your hair.
However, this revival of interest in carrier oils and essential oils for hair care purposes has generated several questions about how long these beauty products last.
For example, does hair oil expire? How can you identify hair oils that are beyond their expiry date? Are there potential problems for your hair and scalp or other consequences for using hair oils beyond their shelf life?
As a general rule, most hair products last about three years unopened, but once you open one and start using it, plan to use it up within about 12 months.
Making things even more difficult, no U.S. law requires expiration dates on hair products (or other beauty products). The FDA leaves it up to each company to work out how long its products last.
Free 9-page planner
Plan your next scalp oil before you mix a single drop.
Our free planner starts with what you’re seeing on your scalp, like flakes, itching, or a wider part. It shows which oil, if any, has been tested for that, and how many drops to add for a wash-out oil, a leave-in, or your shampoo. There’s also a list of the oils that need a weaker mix, a patch test tracker, cards to write down each mix you make, and a log to fill in once a month.
Free. You’ll get the planner by email, then two short emails on using it, and after that one email every Thursday. Unsubscribe anytime.
As much as you might love your all-natural beauty products, this also means that it may be harder to tell when certain products have exceeded their shelf life.
For example, determining when a coconut oil hair serum or hair mask has gone bad is more difficult than identifying expired coconut milk. The milk would clearly indicate an expiration date on the product's packaging, whereas the hair mask may not.
With that in mind, let's take a closer look at hair oils and how to determine their expiry date. We'll also determine when they're "best used by" and how you can tell when your favorite beauty products are starting to go bad.
Does Hair Oil Expire?
Unopened hair oil can last about 36 months before expiring, while opened hair oils are best used within 12 months. Different oils have specific shelf lives, such as grapeseed oil lasting about a year and coconut oil lasting up to 3 years. Proper storage conditions can help extend the life of hair oils. Signs of expired hair oil include foul odor, color change, chunkier consistency, and reduced effectiveness.
Different Oils, Different Standards
Hair oils, like all hair products, expire after a period of time. Unfortunately, the FDA doesn't require beauty products to include an expiration date. If the hair product does include an expiration date, then you should always follow the manufacturer's advice.
However, if there isn't an expiration date included on the product, our general rule of thumb is to throw out an unopened hair product after 36 months. Once opened, we recommend using the product within 12 months or sooner when possible.
To find the date, check the back and bottom of the bottle. You may see a best-by date, or a small open-jar symbol with a number and the letter M, such as 12M.
That symbol is the period after opening (PAO), and 12M means the product is good for 12 months after you first open it. EU rules require one or the other on most beauty products sold there, but U.S. law requires neither, so your bottle may have one, both, or none. If it has neither, go by our rule of thumb above.
Keep in mind that this advice is highly dependent on the ingredients within the product. It's also important to note that DIY shampoo and conditioner recipes need to be used quickly. If your recipe has water in it, or anything watery like aloe vera juice or brewed tea, keep it in the fridge and use it up within a week or two, since water is what bacteria and mold need to grow. Furthermore, different oils will have different standards.
For example, coconut oil usually keeps for 18 to 36 months, though this is highly contingent on the conditions in which you store it. As we'll see later on, the more light and heat you introduce into the equation, the faster hair oils tend to spoil, so stick to recommended temperature storage conditions whenever possible.
Heat matters more than you might think. Oil breaks down about twice as fast for every 18 degrees Fahrenheit (10 degrees Celsius) the temperature rises, so a bottle kept in a steamy bathroom or a hot car will go bad much sooner than one in a cool cabinet.
Coconut oil melts at about 75 degrees Fahrenheit (24 degrees Celsius), so it turns liquid on a warm day and firms up again when it cools. That’s normal and doesn’t mean it has gone bad.
By contrast, let's take a quick look at how other hair oils compare on longevity:
- Almond oil can last between six months and a year, with sweet varieties often doing best.
- Argan oil can last about two years.
- Avocado oil can last up to two years unopened, or about six months once opened.
- Babassu oil can last two years at room temperature and can sometimes be used as a replacement for coconut oil.
- Castor oil tends to be best when used within a year.
- Grapeseed oil can last a year if refrigerated and may spoil sooner otherwise.
- Jojoba oil can last about two years and comes with the asterisk of not actually being an oil but a liquid wax instead.
- Meadowfoam seed oil can likewise last an impressive five years.
- Olive oil can last one to two years.
- Pomegranate seed oil can only typically last about one year.
- Rosehip oil is versatile but shorter-lived than many of these oils, lasting only about six months.
- Sea buckthorn seed oil can last up to a year.
- Sunflower seed oil is another highly versatile carrier oil that can last up to a year.
- Tamanu oil lasts between one and two years, depending on storage conditions.
As you can see, there is a fair amount of variety among these products. Knowing which hair oil you are dealing with can go a long way toward ensuring that you get the most out of it, and that includes increasing its longevity.
Why such a big range? Oil goes rancid when oxygen in the air reacts with its fats, and some fats react much faster than others.
Polyunsaturated fat, the kind that makes up most of grapeseed oil, reacts the fastest. Linoleic acid, the main fat in grapeseed oil, can break down 10 to 40 times faster than oleic acid, the main fat in olive and avocado oil. Coconut oil is mostly saturated fat, which reacts far more slowly, so it keeps much longer.
Jojoba keeps well for a different reason. Since it’s a liquid wax rather than a true oil, it stands up to air better than most oils. In one lab test, jojoba held out longer before breaking down than olive, sunflower, and rosehip oil.
Which Hair Oils Have the Most Fast-Spoiling Fat
Polyunsaturated fat is the kind that goes rancid fastest, so the more of it an oil has, the sooner that oil tends to go bad. Grapeseed oil is about 70% polyunsaturated fat. Coconut oil is about 2%. That gap is a big part of why coconut oil keeps for years while grapeseed oil does best in the fridge.
| Oil | Polyunsaturated fat |
|---|---|
| Coconut oil | |
| Olive oil | |
| Avocado oil | |
| Almond oil | |
| Sunflower oil (high-linoleic) | |
| Grapeseed oil |
The USDA measured these oils as foods. A hair oil pressed from the same plant is made of the same fats. Sunflower oil comes in more than one type, and the high-oleic kind is only about 4% polyunsaturated fat, so check your label. Jojoba and castor oil aren’t food oils, so the USDA doesn’t list them.
Here’s what this means for your shelf. The oils near the bottom of this chart are the ones to buy in small bottles you’ll finish quickly. Keep them capped tight in a cool, dark spot or in the fridge, and give them a sniff before every use. The oils near the top are more forgiving, but heat and air still wear them down over time.
Sources: USDA FoodData Central; Gharby et al., Food Chem X 2025.
Just keep in mind that custom DIY recipes, which are common within the haircare community, change these expiration dates significantly. DIY products are more likely to be exposed to bacteria, contamination, air particles, and more.
When Good Hair Products Go Bad
Lovely as the all-natural life may be, it doesn't spare you from the consequences that can come from using products that have gone bad.
What's more, without the best-by dates that accompany food products, if you aren't careful, you could wind up accidentally using expired hair oils, and that can come with some pretty bad consequences.
But before we get to those, we should first review how you can tell if the hair oil you have is expired, even if it doesn't include an expiry date.
There are several methods for identifying expired hair oil, not the least of which is a foul odor. After all, one of the most pleasing aspects of using many of the all-natural oils mentioned above is that a fine fresh fragrance accompanies them.
There's nothing like the summery scent of citrus or tropical aroma of coconut - and nothing wrinkles the nose faster than the rancidly sour stink that emanates from once-good oils gone bad.
This is especially true of coconut oil, which can also turn yellow when spoiled. Different hair oils will likely turn different hues atypical of their natural state when they go bad.
Also, hair oil that has gone bad will often acquire a chunkier consistency. Think about how your hair oil usually looks and feels when it comes out of the bottle. If it is fresh, chances are it slips out in a nice, smooth stream.
By contrast, your hair oil probably doesn't look, feel, or smell like cottage cheese gone bad. If it does, or if it is chunkier, stickier, or otherwise has suffered a drastic change, that's a pretty clear sign that it is past its natural best-by date. Trust your instincts (i.e., natural concern) and throw out the product.
You should never use anything on your hair or scalp that isn't immediately identifiable. That means that if something is floating in your hair oil that you cannot identify, you probably shouldn't go rubbing it into your hair follicles or scalp.
One of the most prevalent examples of this is the presence of "little black spots" in hair oils, which may indicate mold, bacteria, or contamination - definitely not something you want to inhale or use on your hair and scalp.
In addition, products that have gone bad often experience a drop-off in performance.
Just as milk that has gone bad loses its natural taste, hair oil that has gone bad will often lose its ability to soften, hydrate, and otherwise treat and improve your hair.
If your hair product no longer performs as it once did, chances are it's time to junk it.
The same holds true if your hair oil is leaking through the packaging. A cracked cap or a broken seal lets air in, and air is what turns oil rancid.
Finally, hair oil that has expired can irritate your scalp. Of course, one of the benefits of all-natural products is supposed to be that they are gentler on your scalp and hair than harsher, more chemical-based beauty products.
So if your scalp is starting to become irritated by hair oil that used to be fine, there's a chance that it may be expired.
This matters even more with essential oils. Lemon and other citrus oils are mostly a compound called limonene, and lavender oil’s main ingredients are linalool and linalyl acetate.
These react with air as a bottle ages, and an EU safety review found that once air has changed them, they can cause allergic skin reactions, but when they’re fresh, they rarely do. So keep essential oils tightly capped, and don’t hang on to an old bottle.
Why Hair Oil Goes Bad and its Consequences
There are several reasons why hair oil may go bad, chief among them being poor storage conditions. Too much light, heat, air, or water can cause delicate oils to spoil. Opening the packaging also winds the clock forward on any perishable product's shelf life, hair oil included.
Is It Bad to Use Expired Hair Oil?
Using hair oil that has spoiled isn't harmless. For one thing, it's hard to classify an odiferous, lumpen, sickly-looking, sticky mess as a "beauty" product, and that's precisely what you're left with when good hair oil goes bad.
Even more seriously, rancid oil can be bad for your skin’s health. In a study on rabbit skin, squalene, an oil your own skin makes, barely clogged pores when it was fresh but clogged them badly once it had gone rancid. With oleic acid, the main fat in olive oil, the more rancid it was, the bigger the clogs.
Your scalp is skin, too, so a bottle that smells off doesn’t belong on it.
Should I Use Expired Hair Oil?
No, it's best not to. Once hair oil goes rancid, it won't soften your hair the way it used to, and it can irritate your scalp. If your bottle has a best-by date or an open-jar symbol like 12M, follow it. Without one, go by smell, color, and texture.
What Happens if You Apply Expired Oil?
Over time, oils go rancid. Rancid oil smells sour or stale and can feel thicker or stickier than fresh oil. On your scalp, it can cause irritation, and it won't condition your hair as well. Old essential oils, especially citrus and lavender oils, can also cause allergic skin reactions once they've been exposed to air for a while.
How Can You Tell if Hair Oil Is Rancid?
Rancid hair oil can have an unpleasant odor, and its color may appear darker than usual. Additionally, rancid hair oil may have a thick, sticky texture and can irritate your scalp. To avoid using rancid hair oil, check the date on the bottle, if there is one, and look for any changes in texture, consistency, or smell.
Can I Use Rancid Oil on My Hair?
Using rancid hair oil on your hair is not recommended, as it can irritate your scalp. Additionally, rancid hair oil can be less effective in nourishing and moisturizing your hair, as the oil may have broken down over time.
How Should Hair Oil Be Stored?
Hair oil should be stored in a cool, dry place away from direct sunlight. Exposure to heat and light can cause the oil to break down more quickly and can lead to changes in texture, consistency, and smell. Close the cap tightly after each use, too, since air breaks oil down. It's also important to keep the oil in its original packaging and to avoid transferring it to other containers.
How Long Can I Let Oil Sit in My Hair?
The duration that oil can sit in your hair depends on the type of oil and how it's applied. Generally, oil can be left in your hair for a few hours or overnight before being washed out. However, it's important to follow the instructions on the packaging of your hair oil to avoid any scalp irritation.
Is It OK to Use Expired Olive Oil in Hair?
It's not recommended to use expired olive oil in your hair, as it can lose its effectiveness and even become rancid over time. Expired olive oil can irritate your scalp. If your olive oil is expired, dispose of it, and don't use it in your hair.
Related Articles
- Is It Bad To Use Expired Hair Dye?
- Does Hairspray Expire?
- Does Expired Conditioner Work?
- How to Read Expiration Dates on Hair Products
Don't Use Hair Oils Beyond Their Expiry Date
At their best, hair oils represent a diverse, organic, and potentially reinvigorating way of revitalizing your hair. At their worst, however, they can sour into foul-smelling, spoiled messes that can irritate your scalp.
That being said, as long as you take the time to store your hair oils properly, are mindful of how long they typically last, and watch out for signs of expiration, they can still be soothing and exciting game-changers in your hair care routine.
