by CLEF Skincare on May 28, 2020


At CLEF, we focus on skincare formulations that are safe, minimal, and clinically effective. We believe in only using simple and straightforward ingredients that are directly beneficial for the skin and strengthen the integrity of our formulations—nothing more and nothing less. While much consideration was put into shortlisting the ingredients to include in our products, it’s equally as important to think about what we intentionally left out.

While formulating our best-selling Anti-Aging Copper Peptide Mask, we decided from the start that we would exclude ingredients that could potentially disrupt the health and function of the skin (and the body as a whole). We will always be advocates of ingredients with clinically proven safety and effectiveness without poor or questionable reputations.

In this article, we break down the harmful ingredients to avoid in skincare, and explain why they’re worth avoiding.



Parabens have been widely used as artificial preservatives in skincare products since the 1920s. Preservatives, as their name suggests, are added to preserve the shelf life of products by preventing the growth of bacteria and mold. However, studies have found that parabens not only have the potential to irritate the skin—they can also interfere with the body’s hormone systems. Specifically, parabens mimic the hormone estrogen, which can negatively affect fertility, reproductive organs, and birth outcomes. They have also been found to increase the risk of cancer by influencing other cell receptors to activate cancer genes, which accelerates the growth of cancer cells.

 How to avoid: Look out for butylparabens, methylparabens, and propylparabens (three of the most commonly used parabens) in ingredient lists. 



Drying alcohols are used to make skincare formulations feel lighter, accelerate their absorption, and enhance the penetrability of active ingredients. As the name suggests however, these alcohols can cause dryness and irritation by degrading the skin’s protective barrier, which reduces its ability to maintain moisture. They can also stimulate excessive oil production, which is what leads to those unsightly, mood-ruining breakouts. Alcohol is simply the skin’s worst nightmare, plus it’s basically pro-aging, which is not what you want when looking for skincare with anti-aging benefits.

How to avoid: Look out for ethanol, SD alcohol / denatured alcohol / alcohol denat, methanol, and isopropyl alcohol

P.S. Not all alcohols are bad! Benzyl, Cetearyl, Stearyl, Cetyl, and Behenyl alcohols are a few you can trust. These act as emollients which protect the skin by maintaining its moisture levels.



SLS is the ingredient that gives skincare products the bubbly, foamy consistency that makes us feel squeaky clean. However, SLS dries out the skin by harshly stripping away natural oils, which leads to irritation and allergic reactions. For those with oily skin, the short-term joy of that squeaky clean feeling isn’t worth it in the long-term, since this drying effect can cause the skin to overcompensate by producing more oil, leading to breakouts. SLS is also known to trigger inflammatory skin reactions like eczema and dermatitis. 

Another ingredient with a mystifyingly similar name, sodium laureth sulfate (SLES) is also commonly used as a foaming agent. This is believed to be a better alternative to SLS as it performs similarly but is significantly less irritating on the skin. Phew! If you have sensitive skin however, we’d recommend avoiding both SLS and SLES, just to be safe. 

How to avoid: Simply look out for sodium lauryl sulfate or sodium laureth sulfate.



Mineral oil is a compound derived from petroleum that locks in moisture by forming a barrier on the skin’s surface. It comes in different grades, ranging from the technical grade—used to lubricate engines—to a purified cosmetic grade found in skincare products (e.g., Vaseline petroleum jelly). While the cosmetic grade is considered safe for the skin as it has undergone thorough purification processes, the barrier effect of mineral oils has the potential to clog pores and suffocate the skin. Due to its large molecular size, mineral oils cannot penetrate the skin and thus cannot be absorbed. To get the most out of your moisturising skincare products, always opt for those that absorb into the skin, not those that simply sit on the surface.

How to avoid: Look out for mineral oil, petrolatum, paraffinum liquidum, and paraffin.



Artificial fragrances and dyes are typically added to skincare products to improve their scent and appearance and make them more appealing to consumers. Let’s be honest though—they serve no real purpose, and they're a skin irritation risk not worth taking. 

Fragrance formulations are usually considered company proprietary information (secret formula), which means skincare companies are not required to list out the constituent ingredients and can escape with merely declaring these blends under the single term “fragrance”. One of the most notoriously undisclosed ingredients, known as phthalates, are known to cause inflammation, worsen allergies, and trigger breakouts in those suffering from sensitive skin or eczema. Artificial dyes are also known to trigger allergies, asthma, and cause chromosomal damage, so much so that countries like Norway and Sweden have banned its use.

When subscribing to clean beauty, opt for products that are transparent with the ingredients they use. Not only is this refreshing for your skin—it’s also reassuring for the mind.

How to avoid: Look out for fragrance, Yellow #6, Red #40, and Green #3.



Silicones are a group of substances best known for their ability to form a barrier-like coating on the skin that’s resistant to water and air. Their unique texture gives skincare products a velvety feel that makes for easy applications and leaves skin looking plump and smooth by filling in uneven surfaces. However, silicones don’t provide any actual skin benefits—they make skin look and feel nice in the short-term, but don’t contribute anything long-term. You wash away its superficial benefits as soon as you rinse the product off … if you can, that is. Due to its water-resistant (hydrophobic) properties, silicone-based products are difficult to dislodge from pores, which can lead to, you guessed it, clogged pores! For those with acne-prone and sensitive skin, silicone can trap oil, dirt, and dead skin cells and trigger breakouts. 

How to avoid: Look out for dimethicone, cyclomethicone, cyclohexasiloxane, cetearyl methicone, and cyclopentasiloxane.


Avoid harmful ingredients with CLEF Skincare today!