Should You Straighten Dirty Hair? 5 Things You Need to Know

Can you straighten dirty or unwashed hair? Discover the science of dirty hair and the best routine for straightening your hair in this article.

In today’s fast-paced world, we are always pressed about time. And sometimes, the temptation to turn on the flat iron and get on to our styling routine without washing our hair first is stronger than even the best of us.

However, is this a light mistake that we shouldn’t be worried about, something that we can easily…brush off? Or is straightening dirty hair really that damaging? In this article, we will answer the question “Should you straighten dirty hair?” once and for all.

So, let’s jump right into it:

The science behind dirty hair

Before you say “oh, let’s not get scientific about it and just give me the answer”, just bear with me. Understanding what “dirty” hair means, and what happens when you straighten it, is important to help you make your own conclusions without bias.

What does dirty hair mean?

When we think of the word “dirty”, we usually think about stains and spots, but this isn’t exactly the case with hair. Our hair becomes “dirty” when dirt, dust, sweat, natural oils and residue from hair products build up on the scalp and strands. This leads to an itchy scalp, greasy appearance, and sometimes even an unpleasant odor.

One reason why the hair may get greasy and dirty is due to the production of sebum, the natural oil that our scalp produces to moisturize the hair and protect it from drying out.

Also known as sebaceous glands, the glands in the skin that are responsible for producing sebum are in proximity to the hair roots in the layer of skin known as the dermis.

These sebaceous glands are connected to the hair follicle through channels, which allow the natural oil known as sebum to exit the skin and reach the scalp.

When there is an excess production of sebum, the hair gets greasy. This can happen if we don’t wash our hair frequently, but it can also be a cause of genetics and spike in hormones.

However, the overproduction of sebum isn’t the only cause of dirty hair. Other factors can also contribute to the hair becoming dirty, for example a lot of sweating - a moist scalp becomes the breeding ground for bacteria, which can lead to an unpleasant odor.

Another factor could be the buildup of hair products. If you frequently use hair gels, sprays, primers, or masks without washing your hair for days, they can accumulate on your hair and scalp and create a sticky, dirty feeling,

How often should we wash our hair?

Exactly how often we should wash our hair depends on a variety of factors including hair type, lifestyle, as well as individual needs. For example, an oily scalp requires more frequent washing. However, for most people, washing hair every 2-3 days is the ideal frequency.

Just as not washing your hair enough is not good for you, washing it too frequently isn’t recommended either. Shampooing too often strips the natural oils of your scalp (the sebum), removing the protective layer that the sebum adds to protect your hair from moisture loss.

Washing all natural oils away can lead to a dry scalp and strands that are more prone to breakage.

And now that we have a better understanding behind the science of dirty hair, let's answer the question that you were all waiting for: can you straighten dirty or unwashed hair?

Should you straighten dirty hair?

Put simply, you can't flat iron unwashed hair. When we straighten our hair, we usually use heat styling tools such as a flat iron, which can reach temperatures of up to 450°F (230°C).

Exposing product buildup to high temperatures means that all this dirt essentially gets burnt on your hair, causing a frizzy and lifeless look instead of a smooth and sleek one.

While it could be tempting to straighten dirty hair due to a lack of time or even as a way to fix greasy locks quickly, it is important to note that it doesn’t solve the actual root of the problem.

Over time, the combination of heat and buildup can weaken the hair, making it more prone to breakage and damage.

In addition, sealing this buildup with the flat iron will make it even more pronounced and visible on the hair, which is far from the shiny hairstyle that you are probably aiming for.

What to do instead - 3 steps to straightening hair effectively

Instead of straightening dirty hair and causing unnecessary damage, it is much better to take the time to properly cleanse it and take care of it. Here are a few quick steps on how to straighten your hair without damage:

Step #1: Wash your hair thoroughly

Properly shampooing and conditioning your hair before you start your heat styling routine is essential for keeping it healthy and clean.

Start by choosing products that are appropriate to your hair type. If you are not sure which ones to choose, you can try the NuMe Vegan Tourmaline Shampoo and Conditioner Duo, a powerful combination of hair care products suitable for all hair types.

 

NuMe’s vegan tourmaline products are made with nourishing, natural and beauty-enhancing components - such as tourmaline powder, hydrolyzed quinoa, argan oil, parkii butter and more than 10 amino acids - to ensure proper hydration and shine all day long.

Once you have your shampoo and conditioner of choice, start by wetting your hair thoroughly with warm water. This will help to open up the hair cuticles and allow the products to penetrate more deeply.

Apply a small amount of shampoo to your scalp, and massage gently with your fingertips. Be sure to focus on the scalp, as this is where most of the dirt and oil accumulate.

Repeat the process, then rinse with warm water, and finish by applying a small amount of conditioner to the mid-lengths and ends of your hair. Leave the conditioner on for a few minutes before rinsing again (unless you are using a leave-in conditioner).

If you don't have time for a full wash, try using a dry shampoo or cleansing mist to refresh your hair and scalp. And when you do have time for a full wash, be sure to use a gentle shampoo and conditioner that is appropriate for your hair type.

Step #2: Dry your hair completely

If you thought that straightening dirty hair is bad, wait until you hear about straightening wet hair, which is one of the biggest mistakes that you could possibly make if you want to enjoy smooth, shiny and healthy hair.

Wet hair is more susceptible to damage than dry hair. When hair is wet, it is in a weakened state because the water causes the hair shaft to swell and become more elastic.

This can make wet hair more vulnerable to stretching, twisting, or other forms of manipulation that can cause damage, such as breakage or split ends.

In addition, when we apply heat to wet hair, the heat can cause the water in the hair to evaporate rapidly, which can create steam and cause the hair shaft to expand - in other words, you are effectively boiling your hair, causing irreversible damage.

Put simply, don’t straighten dirty hair and don’t straighten wet hair either as both can be damaging to your beautiful mane. So, it’s best to wait until your hair is completely dry before you start applying any heat to it.

If you don’t have time to let it dry naturally, you can use a blow dryer. NuMe’s Signature Hair Dryer uses negative ion conditioning technology which breaks up water molecules into smaller particles in order to dry the hair faster.

This not only reduces the time for drying, but also causes much less damage to the hair as opposed to regular blow dryers.

 

And last but not least, don’t forget to use a thermal heat protectant to add a protection layer between your hair and the flat iron.

Step #3: Use a flat iron with tourmaline plates and temperature control

Now that we have answered the question “Should you straighten dirty hair?” and explained the process of preparing your hair for effective heat styling, there is one more step that you need to know about.

Not all flat irons are made equal, and some heat styling tools are designed to get you the desired results without the damage that is usually associated with flat irons.

We are talking about the NuMe Megastar Flat Iron - a one-of-a-kind flat iron with proprietary tourmaline technology that seals in moisture and provides quick styling with long-lasting results.

This innovative hair straightener features plates made with crushed tourmaline gemstones - a mineral known for its ability to generate negative ions when heated. Negative ions help to neutralize the positive ions in the hair, which can cause static, frizz, and other types of damage.

When tourmaline is crushed and infused into the plates of a flat iron, it creates a smooth, slippery surface that glides easily over the hair, reducing friction and minimizing damage.

All while helping to seal in moisture and create a smoother, sleeker finish.

In addition, straightening your hair with a flat iron with adjustable heat settings is a must. As we discussed in our previous article, the best temperature for straightening hair will depend on the type and texture of the hair, meaning that you shouldn’t apply the same heat to fine and fragile hair as you would to thick, healthy hair.

The NuMe Megastar Flat Iron goes as low as 200°F (90°C) up to 450°F (230°C). The controlled temperature, combined with the proprietary tourmaline and far infrared heat technologies, ensure that your hair always comes out looking sleek, shiny and undamaged.

Should you straighten dirty hair - conclusion

To wrap it up, the conclusion is simple - no, you cannot straighten dirty or unwashed hair. While it may be tempting to save up on some time, don’t forget that saving this time means causing long-term damage that’s irreversible.

So, shampoo and condition your hair properly, make sure it’s completely dry, apply a thermal heat protectant - and you will be ready to rock your hairstyle without worrying about damage.

FAQ

What happens if you iron dirty hair?

If you iron dirty or greasy hair, you essentially “bake” all the dirt and product build-up into your hair, making it look flat and lifeless instead of sleek and shiny. When hair is dirty, it is also more prone to tangling, increasing the risk of breakage and damage.

Can I iron greasy hair?

No, you can’t iron greasy hair. Ironing greasy hair can cause the oils and dirt on your scalp to be spread throughout the hair shaft, worsening the greasy and dirty look of the hair. Doing this also leads to negative effects for your flat iron, as it becomes more difficult to clean which eventually causes an uneven heat distribution and even further damage to the hair.

Should you wash your hair before straightening it?

Yes, you should always wash and condition your hair before you straighten it, especially if you are doing it with a heat styling tool. High temperatures burn all the dirt, oil and product buildup on your scalp, so you should avoid straightening dirty hair.