Our ingredients

How we select ingredients for our IN-ON-UNDER approach:

Healthy skin starts with a healthy body and mind. Our nutritional supplements provide the support needed to balance and boost health, which in turn improves skin health. Our skin care improves the integrity of the skin barrier and promotes the longevity of healthy skin cells beneath the surface with antioxidants.

The most important factor in choosing dietary supplements is their bioavailability, in other words, their ability to be absorbed by the body. The absorption rate of micronutrients is much more efficient if they are taken with supporting molecules. For example, the vitamin C contained in Acne & Stress is 25% of the Acerola cherry which also contains bioflavonoids to facilitate its absorption. The absorption rate of synthetic ascorbic acid is estimated at 20%, compared to nearly 100% for our vitamin C in food form.


For skin care products to be effective, they must first cross the skin barrier. Here’s a quick explanation of how skin works, followed by how our ingredients bypass this barrier.

The skin barrier and ingredients

The epidermis, the outer layer of the skin, fulfills an essential function in our body, that of defense and protection. To simplify, let's think of defense as "bricks and mortar." It is actually several layers of flattened skin cells (the bricks) "glued" together by intercellular lipids (the mortar). Together, they fight against the elements that try to penetrate, some of which are bad (such as pollutants, allergens) and others good (nourishing ingredients). In this same role of barrier guard, they also try to prevent skin moisture from escaping. This is why the integrity of the skin barrier is essential for skin health.


Since the "mortar" is lipid-based, the skin naturally absorbs oil-based ingredients better than water-based ones. For example, vitamin C is a water-based ingredient and therefore its effectiveness depends on a high dosage and/or a very low pH, both of which can be irritating to the skin.

At Skin Diligent, the selection of ingredients must meet the following 4 criteria:

1. The 10 Pillars of Skin Diligent :

Improve skin appearance, improve skin health, provide cellular protection, respect skin microbiome and pH, never irritate, never sensitize, no endocrine disruptors, no photosensitivity, no side effects, and natural. In other words, all our ingredients respect the health of the skin barrier, its microbiome and skin cells.

2. Ethical and sustainable botanical ingredients :

Our rare but proven botanical ingredients come directly from agricultural cooperatives that practice Pierre Rabhi’s agro-ecological philosophy. This is the case for our Lannea microcarpa , rich in anthocyanins and protective of lipoperoxidation. In Cameroon, we work with hunter-gatherers who collect Ceasalpinia sappan , a powerful cell repairer and protector. At the mouth of the Amazon, we work with an ethnobotanist to collect Protium heptaphyllum , a powerful anti-inflammatory that provides rapid relief. To learn more about our ethical and sustainability credentials, click here .

We also work with local ingredient laboratories that recycle molecules from the agri-food industry in France.

3. Effectiveness :

At Skin Diligent, our favorite vector of effectiveness is the intelligence of delivery systems that help active ingredients reach skin cells. This way, irritation, damage, or sensitization of the skin is not possible. In our acne skin kit, the high-tech delivery system is a modified bentonite clay . A humble but powerful product. This clay is like the brick and mortar of our skin, with the lamellar sheets of bentonite resembling flattened skin cells and the active ingredients sliding around the sheets resembling mortar.

Once applied to the skin, bentonite forms an invisible, breathable film on the skin. This is our "second skin" technology . It absorbs the oxidized sebum produced by the skin and replaces it with active ingredients released throughout the day. The second skin protects the skin and possible breakouts from dirt and pollution. You can find this technology in our Multilayer Serum and our Regulating Moisturizer.

Another advanced system we use is a lysate that acts as a quorum detector. A molecule extracted from Noni , 100% natural and grown in a biotech laboratory, has the ability to control the population of certain bacteria on the skin without decimating them.

We also use encapsulation methods to protect fragile ingredients like the pioneer fermented probiotic strain . Our formulas also contain very rare technical ingredients like lipid-based vitamin C , Ascorbyl tetraisopalmitate. This is an oil-based vitamin C that is easily recognized by the skin and works with the skin's natural pH. It is photoprotective and non-irritating to the skin.

4. The list of SANS

We have chosen not to use the popular preservative ingredient phenoxyethanol, which has single-handedly replaced parabens since many of their forms were banned. Phenoxyethanol is found in everything from shampoos to serums to body creams and more. At Skin Diligent, we have developed a unique alternative system of natural preservatives instead of adopting the industry standard. Our products are:

Free of phenoxyethanol and parabens
Sulfate free
Free of silicones, dimethicones or other petroleum-based ingredients
Without denatured alcohols
Benzoyl peroxide free
Retinoid-free

As a user of Skin Diligent products, even if you are not interested in all the technical details of our ingredients, you can count on us to bring you the best of our knowledge.

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