The dangers of soybean oil for use in cosmetics?

The use of pure soybean vegetable oil is, as a precautionary principle, not recommended for pregnant women, breastfeeding mothers, and young children. This recommendation stems from the fact that it is suspected to be an endocrine disruptor. It is important to note that this is a suspicion and this characteristic is still the subject of debate within the scientific community today.

More specifically, if soybean oil is suspected as a potential endocrine disruptor, it is due to the content of isoflavones in soybean seeds. Isoflavones are classified as phytoestrogens, a family of molecules with a structure similar to that of the natural hormone oestradiol. Phytoestrogens are thus capable of mimicking the action of oestradiol and substituting for it, thereby causing disruptions in the hormonal system.

However, it is important to clarify that soybean oil, unlike soybeans, contains onlyminute traces of isoflavones. When it is extracted, the phytoestrogens indeed tend to remain in the beans. This is why soybean oil is not officially considered an endocrine disruptor, but the principle of caution is applied regarding pregnant women and children, whose hormonal system is more sensitive.

Like any substance applied to the skin, soybean vegetable oil can potentially cause a skin reaction (irritations, redness, dryness...). Although these reactions are rare, to protect oneself, it is advised to perform a tolerance test before applying it to an entire area of the skin. This test is very simple: take a few drops of soybean oil and apply them to the inside of your elbow or behind your ear. Wait for 24 hours and, if you observe no skin reaction, it means your skin tolerates this ingredient.

Another point of caution pertains to individuals who have food allergies to soy. Although a food allergy does not necessarily lead to a cosmetic allergy, it is advisable to seek the advice of a healthcare professional before applying the oil.

Finally, the soybean oil has a comedogenicity index of 2, which makes it slightly comedogenic. People with oily or acne-prone skin can still use it, however, it is preferable for them to apply jojoba oil, hazelnut oil, or even argan oil, vegetable oils that have similar properties to soybean oil but are not comedogenic.