Common Heir Skincare Review

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Written by Leigh Matthews, BA Hons, H.Dip. NT


Leigh Matthews, BA Hons, H.Dip. NT

Sustainability Expert

Leigh Matthews is a sustainability expert and long time vegan. Her work on solar policy has been published in Canada's National Observer.


Common Heir Vitamin C Serum is doing its best to restore a healthy glow to a beauty industry notorious for wasteful packaging and dubious ingredients. This, as the company says, is ‘not your average vitamin C serum’ as it comes in plastic-free packaging and is made without silicones and several other undesirable chemicals. Is it all it’s cracked up to be though? I wasn’t so sure, so I asked the company a few questions and got some interesting answers.

Our Rating: 5/5 (See: How Leaf Score is calculated)

Leaf Score
Table of Contents
  1. Product Highlights
  2. The good
  3. The ingredients
  4. What’s not in the serum?
  5. Is there any research on this product?
  6. Final thoughts

Product Highlights

  • EWG Verified (status pending) vitamin C serum offered in zero-waste plant-based capsules instead of plastic or glass bottles with plastic pump tops
  • Common Heir is a member of 1% for the Planet, a partner to Ocean Blue Project, donates 1% of annual sales, and offers free carbon neutral shipping within the US
  • Small US-based business, minority- and women-owned.
Country of Origin:Made in Korea, packaged and distributed in the US
Ingredients:Isoamyl laurate, Coco-caprylate/caprate, Tetrahexyldecyl ascorbate (vitamin C), Caprylic/capric triglyceride, Castor oil/IPDI copolymer, Neopentyl Glycol Diheptanoate, C13-15 Alkane, Polyglyceryl-6 Oleate, Brassica Campestris (Rapeseed) Seed Oil, Glycyrrhiza Glabra (Licorice) Root Extract, Polyglyceryl-3 Diisostearate, Althaea Offcinalis (Marshmallow) Root Extract, Oryza Sativa (Rice) Bran Extract, Tocopherol (Vitamin E), Glycine Soja (Soybean) Oil.
Certifications:Leaping Bunny certified cruelty-free, EWG Verified

The good

Most vitamin C serums come packaged in plastic or glass bottles with plastic pump tops. Common Heir Vitamin C Serum is made in Korea and packaged and distributed in the US. I asked for more information on the packaging and was told that Common Heir “intentionally avoid[s] coatings, inks or finishes that would impact the recyclability of our tubes. The ink used is all soy-based and the tube is 100% paper and fully recyclable.” Great!

And the serum itself is provide in individual twist-to-open, plant-based capsules that are biodegradable (tested by OECD 301F standards) and can be melted down in hot water. To do this, add the capsules to a glass jar with boiling water and wait 15-20 minutes. The liquid can then be poured down the sink. Or, toss the capsules in the compost.

Common Heir Vitamin C Serum is intended for use on your face and neck to nourish skin before applying moisturizer, sunscreen, or make-up. It can be used daily, day or night, and is fine for storage at room temperature. This makes it a good option for anyone who has to travel frequently for work, or when camping, and just wants to take one or two ‘doses’ of facial serum with them.

The packaging also helps keep the vitamin C serum fresh, unlike with many serums in traditional packaging, where the vitamin C oxidizes quickly. Common Heir says that their serum has a shelf-life of up to 18 months and that it can help prevent and improve the appearance of dullness, dark spots, and aging.

So, what is actually in the serum?

The ingredients

Common Heir Vitamin C Serum is EWG Verified, though it is still listed as EWG 2 on the EWG site. Common Heir confirmed via email that the Verified status is confirmed but EWG is yet to update the listing; I’m waiting for EWG to confirm this but have no reason to doubt Common Heir here.

The serum contains the following ingredients:

Isoamyl laurate, Coco-caprylate/caprate, Tetrahexyldecyl ascorbate (vitamin C), Caprylic/capric triglyceride, Castor oil/IPDI copolymer, Neopentyl Glycol Diheptanoate, C13-15 Alkane, Polyglyceryl-6 Oleate, Brassica Campestris (Rapeseed) Seed Oil, Glycyrrhiza Glabra (Licorice) Root Extract, Polyglyceryl-3 Diisostearate, Althaea Offcinalis (Marshmallow) Root Extract, Oryza Sativa (Rice) Bran Extract, Tocopherol (Vitamin E), Glycine Soja (Soybean) Oil.

Everything on this list has a rating of 1 (meaning it’s likely very safe) with the exception of a couple of ingredients that are associated with some problems but that I’m not too concerned about, and one ingredient that needs further attention.

The first two are:

Glycyrrhiza Glabra (Licorice) Root Extract – this plant extract is said to improve skin brightness and circulation and is EWG rated 5, i.e., restricted but safe when used as directed. This extract poses a low risk of neurotoxicity and irritation of the skin, eyes, or lungs, as well as a moderate risk of endocrine disruption and non-reproductive system organ toxicity. Realistically, though, these risks are mainly associated with ingestion of the plant extract, and the likelihood of skin irritation or other topical effects is low and minor in severity.

Oryza Sativa (Rice) Bran Extract  – a soothing ingredient, this may also help to brighten skin and has an EWG rating of 2 as it is at risk of being contaminated with pesticides (because these crops are often heavily sprayed with such chemicals). It would be great to see Common Heir use an organic rice bran extract instead.

This serum also contains a small amount of soy and could potentially contain trace amounts of gluten, with the silicone replacement, isoamyl laurate, potentially including trace amounts of wheat and barley from the extraction process to ready the material for cosmetic use.

Finally, the ingredient that concerned me the most (and led to a great learning opportunity!):

C13-15 Alkane – typically a petroleum-derived material that acts a little like silicone for that lubricating feel.

Because this chemical is considered petroleum-derived in every chemical database I checked – it comes from treating petroleum with hydrogen in the presence of a catalyst and is restricted under the European Union’s REACH legislation – I asked Common Heir why they claim it is a plant-derived ingredient. A company representative told me that their C13-15 is “100% plant-derived, palm-free and does not contain substances of petrochemical origin, according to documentation from our supplier.” Specifically, “this material is part of a specialty ingredient blend and the alkanes are obtained by hydrotreating brassica campestris and coconut fatty acids.”

So, it’s great that this formula remains 100% plant-based, but does this natural origin matter? Turns out that it does! While EWG lists petroleum-derived C13-15 alkanes as rated 3 for a variety of good reasons (more on those in a moment), the plant-derived version is rated 1. I’m grateful to Common Heir for working with me on figuring out the difference between these chemicals here as it’s pretty perplexing to have two listings for seemingly the same chemical but with significantly different environmental and health impacts.

C13-15 alkanes from petroleum sources are associated with non-reproductive organ system toxicity (low) and irritation (skin, eyes, or lungs) (low), in addition to being a known carcinogen. These chemicals may be fatal if swallowed and harmful or fatal if inhaled, and may cause damage to organs through prolonged or repeated exposure. Oh, and for good measure, it is toxic to aquatic life, with long-lasting effects. Given the toxicity to aquatic life, I would not want a formula using petroleum-derived C13-15 alkanes to make its way into streams and rivers, which is why I initially questioned just how ‘green’ and ‘clean’ Common Heir could really be and the safety of melting down those capsules and pouring them down the sink or putting them in compost at home or in municipal composting facilities.

Obviously, you still won’t want to swallow the capsules or inhale the ingredients. But, plant-derived C13-15 alkanes do not bioaccumulate, are non-carcinogenic, are not listed under REACH as toxic to aquatic environments, and have no other health or environmental concerns.

Thankfully, Common Heir have been highly transparent and communicative, backing up their claims that they ‘don’t believe in greenwashing’ and that they avoid carcinogenic ingredients and known hormone disruptors as well as ingredients known to pollute waterways, airways, and the environment.

What’s not in the serum?

Common Heir also get good grades for their serum being fragrance-free and free of parabens, phthalates, polyethylene glycols (PEGs) and silicone. The coconut-derived ingredients and palm-oil derived ingredients are also certified by the Roundtable on Sustainable Palm Oil (RSPO), although this body is of questionable merit as a true test of sustainable palm oil and it’s definitely best to just avoid palm oil altogether.

The vitamin C serum is vegan-friendly and Leaping Bunny certified cruelty-free and Common Heir use packaging and shipping materials that are completely plastic-free, readily biodegradable, or recyclable. The inks and coatings don’t impact material recyclability or safety.

Is there any research on this product?

One very small study has been carried out to assess the effects of Common Heir Vitamin C Serum. This study only involved 40 women aged 18-55, and no details are provided as to whether it was double-blinded, randomized, controlled, or had any methodological merit.

Common Heir’s published results from the study state that after 4 weeks, 87% of subjects saw smoother, visibly brighter skin and said skin felt more hydrated and healthier-looking, with 82% seeing visible improvement in texture and more even skin tone. This suggests the results were self-reported by participants rather than being assessed by a clinician blinded to the treatment.

Participants in the study also overwhelmingly (98%) said they had no problems applying makeup or other skincare after applying the serum and 73% reported smoother-feeling skin after just one use.

I asked the company for more information and was told that they “took the extra step of investing in third-party studies conducted by an independent third-party lab (Citrus Labs) specialized in clinical trials with study design, clinical protocol.” On follow-up, the company added that this was a “single-group, non-randomized, single intervention-treatment study with as many subjects as we could source under our budget” and that they “measured and reported consumer perception.” And, as with so many things, even if this small business could have afforded a more robust and expensive study involving dermatological testing in lab or clinic, the pandemic would have prevented their participants traveling to such appointments anyway.

It would still be nice to see the raw data or any further useful information on the study, but for now, given their overall transparency and goodwill, I’m happy to take Common Heir at their word that “The results on our website accurately reflect the final study report provided to us by our research organization.”

Final thoughts

Common Heir is a member of 1% for the Planet and a partner to Ocean Blue Project. The company donates $1 from every email signup, which is the equivalent of removing a pound of microplastics from the ocean. They also donate 1% of annual sales and offer free carbon neutral shipping within the US. They don’t currently ship internationally.

You can give this serum a whirl for $88 for a two-month supply, and I’d strongly recommend this EWG Verified vitamin C serum over pretty much every other such serum out there. I’d still like to see a more robust clinical trial, so here’s hoping Common Heir gets the attention it deserves and this business, which has a clear commitment to health and the environment, can afford such a study in the future.

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