What are the side effects of the harsh ingredients in conventional shampoos?

Conventional shampoos are worrisome  mainly due to two ingredients commonly found in their containers: surfactants like SLS (Sodium Lauryl Sulfate) and preservatives like parabens. A lot of ink has been spilt about the possible side-effects of these substances, some of it is just blatant fear-mongering, while the rest is based on scientific inquiry. Discerning the one from the other can be difficult in the internet age. This post aims to give you a brief overview of some of the risks, without hype or alarmism.

Give me an S, give me an L, give me another S, what do you get? Irritation

SLS made headlines in recent decades when some scientists found links between the substance and cancer. Though later investigation found those assertions to be overstated, there are other reasons to be skeptical of the chemical.

One study at the American College of Toxicology found that skin irritation can occur when concentrations exceed one percent — this is especially disquieting because concentrations of between 15 – 20 percent are not unheard of in most shampoos. The scientists also found that higher concentrations led to severe irritation and even corrosion of the skin.

Corrosion? That sounds a little drastic, doesn’t it?

To understand how they arrived at that conclusion you have to get a sense of how SLS works. In essence the surfactant operates by starting a process called protein denaturing. That is to say, one part of it connects with fats while the other attaches to water. This allows you to rinse off the greece when the water is discarded. The problem is that the process works both on the fats attached to your hair as well as to the cells on your scalp. Over time this denaturing process can cause irreversible damage.

SLS and Children

SLS has been linked to eye irritation and poor eye development in children. This happens even at low concentration levels. Even more alarming is the fact that SLS can be absorbed through the skin. Some studies have shown that this means the substance can accumulate in the one’s liver, heart and brain. On average the body seems to be able to get rid of SLS after about four to five days, but considering that many people wash their hair daily or every second day, it is possible that the surfactant can remain permanently in your body.

Putting SLS to the test

Professor Richard Guy at the University of Bath’s Department of Pharmacy and Pharmacology conducted an experiment with the BBC recently, to ascertain the toxicity of SLS.  He started by putting liquid SLS, at a concentration lower than that generally found in most washing products, onto the skin of his colleague, Dr Chris van Tulleken. He did this for six hours daily, for 21 days. Guy then measured the rate at which the skin lost water before the experiment and then again at the end. Guy says that the rate of water loss is a good proxy for the skin’s ability to be an effective barrier (protector) against pathogens. In other words, if more water is lost then that is a clear indication of damage to the skin.

Results? Guy found that water loss from his colleague’s skin had gone up three fold, from 9g per square metre of skin per hour to 33 g/m²/h. He told the BBC that the change in water loss from was about halfway toward completely losing the upper most layer of the skin.

Paraben paraboom

Parabens are raising eyebrows and heart rates primarily because they behave as estrogen (the female sex hormone) mimics. Some scientists have suggested that this may cause breast cells to divide more rapidly and ultimately lead to cancer, though this finding has not been conclusively confirmed in the scientific community.

The risk is however not limited to women. Several studies have found that men who have parabens absorbed through their skin due to repeated use of various cleaning products had lower sperm counts in addition to subdued testosterone levels.

It must be stated that several scientific oversight committees have evaluated parabens and have arrived at somewhat different conclusions. For instance the U.S. Food and Drug Administration, and the Cosmetic Ingredient Review (CIR) have come out as saying that parabens are safe at current exposure levels. But researchers such as the U.S. Environmental Working Group have expressed concern about the cumulative impact of using the product. That is to say, using one deodorant may not be of concern, but using shampoo, under-arm spray, and a whole host of other products may eventually take its toll on your health. More research is being done.

Can chemicals in my cosmetics get into my body?

How toxins get into our bloodstream

How toxins get into our bloodstream

The skin is our largest and one of our most important organs. It does the indispensable job of keeping us cool and protecting us against the elements. The only downside to having it is that we have to endure a phase during puberty in which it becomes a pimply repellent against the opposite sex.

But what happens when the skin is not able to carry out one of its key functions? What happens when chemicals manage to break our skin’s defences? Is it possible, for example, for the cosmetics we put on our skin to make it into our bloodstream and cause damage from there?

Skin 101

There are three layers to our skin:

  • a top layer (epidermis),
  • a middle one (dermis)
  • and an inner one (hypodermis).

As you might expect, the top layer is our first line of defence, it has a fat buffer and many blood vessels inside it. This layer is lipophilic (oil-loving) and hydrophobic (resistant to water), a feature which accounts for the fact that we do not fill up with water every time we step into the shower or swim in the ocean. Oils typically make it into the upper layer (penetration) but this is most often as far as they go. The other layers further below have a different chemical composition, making it more difficult for oil to go any deeper.

This means that most oils won’t make it into your bloodstream. There’s too much water in our bodies and too many layers of cells to prevent this. But does this mean that we don’t have to worry about chemicals in our cosmetics? Not quite.


The cosmetics industry has found clever ways of getting past these epidermal security guards: Through a process called emulsification, oil and water are mixed. It’s a bit like how mayonnaise is made — the blending of a water-based ingredient (mustard and lemon juice) with an oil is achieved using an egg yolk, which binds them. Modern cosmetics function similarly. They use emulsifiers to blend oil and water, making it easier to penetrate your skin.

What about the skin’s defences?

The good news is that the skin is savvy enough to deal with even the intruders that come through with emulsifiers. Also, many molecules are simply too big to get through. Others remain on the skin’s surface and still others bind with the skin itself. Those that do seep through will encounter enzymes that break down or inactivate toxic chemicals. There are however some that may do the opposite, i.e. they activate chemicals, making them more toxic. For example, in 1775 Percivall Pott, a British doctor, found that contact with polycyclic aromatic hydrocarbons in soot was causing chimney sweeps to get cancer.

Absorption and penetration

When it comes to chemicals in cosmetics, it is important to distinguish between penetration (simply getting under the skin) and absorption (breaking into the bloodstream). Penetration is not necessarily problematic because once a substance enters the body, it may be turned into another chemical or metabolized by the body.

The other alternative is that it accumulates. This is where things get tricky because when it comes to toxicity often the dose is the deciding factor (many otherwise non-harmful substances can become toxic at high concentrations). Our bodies have a theoretical threshold at which the accumulated amount of a substance becomes unsafe. This point is different for each person.

So the answer to the question, “Does our body absorb what we put on our skin” is “yes and no”. Some substances definitely do make it through — especially if aides like emulsifiers increase absorption rates, but it is hard to provide a generally applicable formula. Governmental bodies like the FDA limit the amount of ingredients that can be used to increase absorption rates, but as discussed here, FDA regulations are not always full-proof.

So what should you avoid?

As mentioned above, exposure is the key factor to consider when it comes to chemicals. For example, something you splash onto your face briefly will have a different effect on your skin compared to a lotion that you put on your body and allow to soak in all day. That is to say, be extra careful with products that are exposed to a large surface area (e.g. body creams, bath salts). Shampoos make it onto that list as well as the foamy residue eventually runs off onto your entire body.

Parabens and formaldehyde are some of the most worrying chemicals you would do well to avoid. Parabens are preservatives which have been shown to be estrogen mimics. These can have adverse effects on your hormonal household, so much so that many of them have been banned by the EU. Formaldehyde has been linked to cancer in a high publicity lawsuit against the multinational cosmetics manufacturer, Johnson & Johnson. Both of these could get into your bloodstream through your shampoo, so it is advisable to get a plant-based alternative for some peace of mind.

Photo by Isabell Winter on Unsplash

What shampoo ingredients should I avoid during pregnancy?

What shampoo ingredients should I avoid during pregnancy?

Once the pregnancy hormones are deployed into a woman’s bloodstream, cravings and nausea are not the only result. Unfortunately even her hair will not be spared. And in typical hormone style, the particular manifestations can be quite unpredictable. For some women dry hair could become oily, others could see their curly hair relax or still others might find that a dye suddenly produces a different hue to what they’re used to. Not to mention the fact that some women might sprout new hair in places they’d only ever seen on their most annoying uncles (that’s right, we’re talking face and back).

There’s no changing those hormones, sadly. There are however other risks associated with pregnancy that you can do something about. For one thing there are a number of chemicals in shampoos that could be harmful to your baby. PureRescue has compiled a list of some of the most troubling ones to steer clear of.


Maura Henninger, a naturopathic doctor from New York City, discussed the dangers of parabens in an interview with mom magazine. According to Henninger, parabens (often listed as sodium methylparaben, methylparaben, ethylparaben, propylparaben and butylparaben) are ingredients found in shampoos that you should avoid. The main concern with these substances is the fact that they act as estrogen (the female sex hormone) mimics. “Research shows that they may disrupt hormone balance and are thus a danger to the proper development of the fetus,” Henninger warns.

Further studies are required to ascertain exactly what effect parabens will have unborn babies. It is possible that they are more vulnerable to effects of hormone irregularities.

Vitamin A

A study in the 1990s indicated that excessive amounts of vitamin A can lead to birth defects in children. The babies of women who consumed more than 10,000 units of vitamin A every daily — which translates to four times the recommended levels — were more likely to be born with abnormalities in their head, heart, brain or spinal cord.

It must be noted that these studies refer primarily to supplements. According to the Linus Pauling Institute, supplements should remain below 3,000 mg/day. The amounts of vitamin A found in shampoo is generally lower but the conclusions reached in the studies are enough to warrant caution with the ingredient — at least for the first trimester of pregnancy.

Sodium Laureth Sulfate

Sodium Laureth Sulfate (SLES), which is not the same as Sodium Lauryl Sulfate, is a foaming agent found in soaps and shampoos that has been linked to cancer and some birth defects. Be sure to read the packaging to make sure that the phrase “SLES free” appears.

Methylisothiazolinone (MIT)

MIT is a substance used to kill harmful bacteria that would otherwise thrive in the moisture of shampoos or lotions. The substance aroused concern in the early 2000s when a study found that MIT can disrupt our cells’ ability to communicate with their neighbors.

The study found that prolonged exposure to even small amounts of the chemical damaged the development of nerve cell structures called dendrites and axons. These structures play an important role in allowing cells to transmit signals to each other. The initial tests were done on rats but the researchers expressed the concern that the effect could be similar with unborn babies.

Ingredients to seek out

Fortunately there are a number of natural shampoos and conditioners that avoid the harmful substances mentioned above while still providing you with healthy, radiant hair throughout your pregnancy. When you are selecting your brands, try keep an eye out for a few ingredients that are particularly helpful. Shea butter is one such substance. It helps hair retain its moisture and thereby prevent breakage. Similarly coconut oil also helps infuse your hair follicles with moisture and vitality.

Of course aloe vera is another wonder ingredient that can help prevent hair loss as the gel provides your scalp with essential amino acids for a healthy sheen.

Bottom line

Pregnancy can be stressful enough without having to spend your time screening shampoos for harmful chemicals. By choosing plant-based alternatives you can skip all that and gain much needed peace of mind.

What are the most potentially harmful ingredients in conventional shampoo?

The marriage between modern science and commerce has produced some beautiful children over the years. For example, space rockets, segways and Michael Jackson. But of course science and capitalism have also produced some weird children too. That’s right, we’re looking at you, cosmetics industry.

Over the last 100 years or so big companies have enlisted the help of the best geeks to produce products that make our lips more luscious, the angle of our cheekbones more acute, and of course our hair more vibrant. Because these scientists have also been instructed to keep costs low, eventually society has ended up with a whole bunch of chemicals that may do all of the above, but at considerable risk to our health. In other words: while they were focusing on the cosmetic aspects, some health concerns may have fallen by the wayside. Below is a brief overview of two of the most worrying ingredients found in your shampoo.

Sulfate self-hate

Sulfates are a frothing ingredient found in many cosmetics and cleaning materials. They will usually be listed as SLS (sodium lauryl sulfate), sodium laureth sulfate (SLES), or ammonium laureth sulfate (ALS) — all words worth at least 35 points in scrabble. Basically, they are used to dislodge dirt and oil from your hair.

SLS and ALS are both considered anionic surfactants but are quite different in their molecular structures. ALS is much larger which means that it’s less likely to penetrate your pores. SLS, on the other hand, is the chemical that often gets written about because it is small enough to literally get under your skin and possibly cause irritation, reddening and erythema of the epidermis.

In America the U.S. Food and Drug Administration has required that manufacturers carry a warning label about the dangers of swallowing too much toothpaste (which contains SLS) because of the risk of diarrhea. Also, some studies have shown that SLS has been linked to irritation of the skin and eyes, organ toxicity, developmental/reproductive toxicity, neurotoxicity, endocrine disruption, ecotoxicology, and biochemical or cellular changes.

To be fair, when it comes to toxicity you have to keep dosage and exposure in mind. After all, high concentrations of cinnamon oil would be toxic on your skin. A shampoo containing 15 percent SLS can be sold to the public because it generally comes into contact with your skin for just a few minutes and is diluted by water. Still, these levels are broadly determined with the average person in mind. The fact that you’re reading this probably means that you have had some kind of negative reactions on your skin as a result of using conventional products, which means you have reason to be more cautious than most.

Parabens bans

Parabens belong to the family of esters of para-hydroxybenzoic acid. There are all sorts of technical names for the various kinds, such as methylparaben (E218), ethylparaben (E214), propylparaben (E216) and butylparaben, which are the most common. They are antibacterial and antifungal agents, which is why they are used as preservatives. They can even be found naturally in food such as strawberries or peaches, as well as in the human body.

Like sulphates the toxicity of industrially produced parabens depends on the degree to which you are exposed to them. Though each product typically stays within government stipulated limits, it becomes harder to track the cumulative effect of these products given that they are found in so many products. In other words: Using one manufacturer’s products won’t be very problematic. Using many different ones over a lifetime could start to add up.

Parabens are worrying because they tend to disrupt hormone function, an effect which some have linked to breast cancer and reproductive toxicity, according to the NGO Campaign for Safe Cosmetics (CSC). Parabens function as estrogen mimics. That means your body perceives an increase of estrogen levels which is said to trigger a more rapid division of breast cells. It must be said that new research suggests that the link between parabens and cancer is inconclusive. But this is not just a matter scientific “he said, she said”. At the end of the day, the risk parabens pose is so severe that in 2014 the EU banned five specific parabens from being used commercially.

Bottom line

There probably isn’t a mass conspiracy to give you cancer through your shampoo. Regulators are very careful about the concentration of chemicals that they allow you to get exposed to. At the same time, specifically sulphates and parabens have made their way into so much of our everyday products that the cumulative effect is beginning to be problem — especially when it comes to a product that some literally use every day. Fortunately there are a number of natural alternatives that clean you well without incurring unnecessary risks.

So what are the safe alternatives? Well yes, this is the part where we make a shameless promotion of our products because they are safe, natural alternatives. Have a read about them here, or first read on about the wonders of natural alternatives.