Everyone loves soft, shiny, manageable hair, and when you find a cheap and chemical-free way to achieve it, that’s even better!
Hair oils are a popular remedy for dry, damaged, or coarse hair, which you can buy as commercial hair care products or make your own DIY home remedies. But what is penetrating hair oil, and how does it work?
In this guide, we’ll explain the difference between penetrating and sealing oils. We’ll also answer questions like what’s the best way to use hair oils, and what does hair penetration mean?
What Is Penetrating Oil?
For centuries, people have enjoyed using the nourishing and lubricating properties of plant oils to pamper their hair. While it’s true to say that you could use almost any oil on your hair, some will be too heavy for your locks.
There are also certain plant oils that offer additional benefits for hair health, so how do you know which oil to use?
What’s the difference between Penetrating Oil and Sealing Oil?
We can generally divide most oils into two types: penetrating oils and sealing oils. Although, just to complicate things, some oils will both penetrate and seal your hair!
Penetrating oils are also known as moisturizing oils, and this group includes oils like olive oil, avocado oil, and almond oil. They can penetrate the hair shaft, which allows them to deliver moisture deep inside your strands, helping to strengthen them and prevent breakage. These oils are also naturally hydrophobic, which means they can stop your strands absorbing too much water.
These oils are ideal for restoring the softness and manageability of coarse, rough feeling hair and sun-damaged or heat-damaged hair. They’re also great for low porosity hair, which has a tightly closed cuticle that makes it difficult to get moisture into the hair shaft.
You can use moisturizing oils on their own or mix them with a leave-in conditioner to make it easier to distribute the oil evenly.
Depending on your hair type, you might find that penetrating oils leave your hair feeling weighed down. If so, you could try using a sealing oil. Some popular sealing oils include black castor oil and jojoba oil, along with shea butter.
These oils sit on top of the hair shaft and seal in moisture, so they’re better used after thoroughly moisturizing your hair. Sealing oils are generally heavier, keeping your hair softer and shinier for longer.
Sealing oils are great for high porosity hair, which has a more open cuticle than lower porosity hair. This means the hair shaft absorbs moisture easily but then loses it quickly, so applying a sealing oil to high porosity hair will help prevent moisture loss.
If you’re unsure whether you have high porosity or low porosity hair, our Guide to Hair Porosity will help you work it out.
Penetrating and Sealing Oils
Finally, there are a few oils that will both penetrate and seal your strands, which include grapeseed oil and argan oil.
However, remember these oils leave a thinner coating on your strands than true sealing oils.
What are the Benefits of Using Penetrating Oils for Hair
These oils are a fantastic treat for your locks, and here are just a few of the benefits they offer.
Can strengthen hair
Hydrating hair oils are packed with vitamins and minerals essential for good hair health. Applying these moisturizing oils to your hair and scalp is a great way to give your mane a nourishing boost that will keep it strong and healthy.
Can soften hair
Moisturizing oils can penetrate deep into the hair strand, delivering hydration that increases its elasticity. You’ll find that your hair becomes softer, more supple, and less prone to breaking.
Your hair naturally contains lipids, or fats, that help make your mane shiny. These can be lost through damage from heat, chemicals, and environmental pollutants, but the fatty acids in moisturizing oils will add extra shine to your locks.
May promote hair growth
Although there’s no guarantee, using hair oils to massage your scalp and coat your strands could help encourage healthy hair growth.
That’s partly down to the increased blood flow to your scalp and partly because the increased hydration in your strands helps reduce breakage.
Shields from damage
Moisturizing oils add a protective layer that can help shield your strands from environmental stressors including UV light. If you choose an oil with a smoke point of 350°F or higher, like coconut oil, it can also protect your locks from damage caused by hot styling tools.
Can protect against hygral fatigue
Penetrating oils have water repelling properties when applied to dry strands as a pre-shampoo treatment. This helps prevent the hair strand from soaking up too much water, which can lead to hygral fatigue.
Can prevent dandruff
Exfoliating your scalp and following up with an application of oil is a great way to reduce dry, flaking skin. Scalp massage with an oil will also encourage the production of your natural anti inflammatory and antifungal sebum.
Always choose one of the moisturizing oils listed below to avoid blocking the pores on your scalp.
6 Penetrating Hair Oils
If you’d like to experience the moisturizing power of penetrating hair oils, here are six fantastic oils to try out:
Coconut oil is one of the most popular moisturizing oils. It’s very effective at boosting hydration, preventing protein loss, and leaving your tresses with a beautiful shine.
However, being popular doesn’t mean it will suit everyone, and you might find that coconut oil leaves your locks feeling heavy and greasy.
Avocado oil is packed with fantastic hair nutrients like biotin, vitamin A, and vitamin E that will help strengthen your hair and prevent breakage to help you reach your hair length goals. It is a great detangler and can also be used to soothe and moisturize a flaky scalp.
Many people have olive oil in their kitchen, so it’s an easy option for moisturizing your hair. As well as penetrating your hair to deliver hydration deep into the strands, olive oil helps smooth your cuticles and seal split ends.
Sunflower oil is another lightweight oil that’s often found in the kitchen. It’s rich in nutrients like antioxidant vitamins A, C, and E and essential fatty acids, and ideal for fine hair that’s easily weighed down.
Babassu oil comes from the babassu palm tree (Attalea speciosa), which grows in northern Brazil. Like coconut oil, it’s solid at room temperature, so you’ll need to melt it gently before applying it to your hair.
However, babassu seed oil is lighter than coconut oil and less likely to leave your hair feeling greasy. It’s a great choice if you have coily or kinky hair that can tend to be very dry.
Almond oil is rich in nourishing vitamins and minerals like antioxidant vitamin E and magnesium, which are essential for a healthy scalp and strong hair growth. Almond oil delivers moisture deep into your hair strands and is an excellent option for scalp massage.
How Penetrating Hair Oils Work
If you’re considering using a hair oil, it’s essential to know whether the oil you choose will penetrate or seal the strands. That’s decided by the fatty composition of the oil.
Monounsaturated, polyunsaturated, and saturated oils all contain fatty acids, which are formed from long chains of hydrogen and carbon atoms. The length of the chains in the saturated, monounsaturated, or polyunsaturated fatty acids is what determines whether an oil will penetrate or seal a hair strand.
- A short-chain fatty acid will penetrate the hair strand.
- A medium-chain fatty acid may or may not penetrate the hair strand.
- A long-chain fatty acid won’t penetrate the hair strand.
Penetrating oils tend to be saturated or monounsaturated fatty acids with a compact molecular structure, short carbon chains, and a slight positive charge. Their short chain fatty acids will penetrate the hair shaft and deliver essential moisture, nutrients, and proteins inside the cortex to benefit the health of your hair.
How To Use Penetrating Hair Oils
A penetrating oil works better when it’s warmed first , either between the palms of your hands or by heating very gently in a small pan. Avoid heating it in the microwave as it’s easy to overheat the oil and scald yourself.
There are various different ways to get the most out of these moisturizing oils:
LCO Method and LOC Method
These are two very popular methods of boosting moisture in curly hair. The LOC method involves layering a Liquid or Leave-in conditioner, a penetrating Oil, and finally, a Cream to lock in hydration. The LCO method is similar, but the oil and cream are reversed.
A pre-poo or pre-shampoo rinse is a really effective treatment for your mane. Before washing, section your hair and apply the oil to each section, ensuring you coat each strand down to the ends.
Leave the oil to work its magic for 10-15 minutes, then shampoo and condition your hair as usual.
You can learn more about doing pre-poo treatments in our Pre-Poo Guide.
Hot Oil Treatments
Hot oil treatments are a great way to infuse hair with additional moisture and help reduce breakage. Gently warm one of the oils above with a couple of drops of your favorite essential oils (not in the microwave!) for a hair treatment that smells great.
Massaging a few drops of oil into your scalp is a great way to moisturize your scalp skin and stimulate blood flow to your hair follicles.
It’s essential to use a penetrating oil as a sealing oil could clog your pores and cause scalp acne and stunted hair growth. Coconut oil, babassu oil, and almond oil are all good options for scalp massage.
What are the Best Penetrating Oil Hair Products?
There isn’t a one-size-fits-all answer to this question. For example, some people find that coconut oil works wonders on their tresses, while others find that it leaves their hair greasy.
The natural oils mentioned in this article are all fantastic moisturizing oils. So, the best advice is to try some of the oils listed above and see which work well on your hair.
Still wondering about using moisturizing hair oils? These are some of the most frequently asked questions on this topic:
Is It Better to Apply Penetrating Hair Oil To Wet or Dry Hair?
This depends on how you want to use your oil. You can either use your oil before you shampoo as a pre-poo treatment or layer it on wet hair with conditioners and creams as part of the LOC or LCO method.
Can I Leave Penetrating Hair Oil Overnight?
Opinions vary on this. Some people believe that an overnight treatment will give even more benefits for your hair, but on the other hand, others say that it could cause scalp acne, blocked follicles, or even hair loss.
To be safe, leave your oil on for no more than 1-2 hours for higher porosity hair, and up to 5 hours if you have low porosity hair.
Can Moisturizing Oils Address Issues of Hair Loss and Thinning?
Unfortunately, there’s no scientific evidence that hair oil will reverse hair loss or thinning. However, it may improve your scalp health and reduce breakage, and could encourage hair growth by stimulating your follicles.
Can I Use Penetrating Oil on Color-Treated or Chemically Processed Hair?
Moisturizing oils can cause interactions with chemicals, so using them straight after a color or other chemical treatment is not recommended. Your stylist or colorist will be able to advise you on how long to wait and the best way to use your oils.
Is Shea Butter a Moisturizer or Sealant?
Butters like shea butter tend to contain more saturated fatty acids like stearic acid, making them more solid than liquid oils. This also means that shea butter can’t easily penetrate the strand, so it works better to seal dry strands.
Some butters have low levels of lauric acid, so they can slightly penetrate your strands, but they work better on thick, high porosity locks.
The Bottom Line
Penetrating oils can make coarse, dry, or damaged hair feel softer and healthier. They can also help your strands repel water to avoid hygral fatigue, and soothe an itchy, flakey scalp.
These natural oils are a low-cost, clean way to give your locks a boost of essential moisture and nourishment, and there are several easy ways to make them part of your hair care routine.
So why not try out a few different oils to see which makes your mane look and feel amazing!