What should you know about nettle?

The nettle belongs to the Urticaceae family and is part of the botanical genus Urtica, which encompasses numerous different species of nettles. They all share a common ability to sting. Indeed, upon contact with the skin, their leaves trigger an inflammatory reaction on the skin's surface. However, some species prove beneficial for the body, skin, and hair. This includes the stinging nettle, or Urtica dioica, and the small nettle, or Urtica urens.

• Urtica dioica.

  This refers to a perennial herbaceous plant ,meaning it can live for several years. It thrives in temperate regions and primarily grows in rich soils. The dioecious nettle measures between 50 cm and 1 m in height. Its leaves have a dark green color, almost black on the top, and are lighter underneath. As for its roots, they are creeping and develop rhizomes.

• Urtica urens.

  The burning nettle distinguishes itself from the dioecious nettle by its smaller size, approximately 40 cm. Furthermore, it is an annual plant, not a perennial. The burning nettle can thrive in uncultivated areas such as meadows or forests. Its leaves are lighter on the top. Unlike the common nettle, the burning nettle has taproots and does not possess rhizomes.

It is possible to obtain an extract rich in molecules beneficial for the skin and hair from the leaves of the nettle. The table below summarizes the various active ingredients found in the nettle extract, as well as the main properties associated with them. Percentages are not indicated as these vary depending on the variety of nettle and the extraction method used.

When applied topically to the skin or hair, nettle has numerous benefits.

• Purifying.

  Thenettle extract is a favored ingredient among individuals with oily skin. The benefits of nettle for this skin type can be attributed to its ability to inhibit 5-α-reductase, the enzyme that catalyzes the conversion of testosterone into dihydroxytestosterone (DHT). When DHT binds to a cytosolic receptor in the sebaceous glands, it intensifies sebum production. By inhibiting this process, nettle helps regulate oily skin.

• Anti-inflammatory and soothing.

  Studies have shown that nettle works at various levels to reduce inflammation. One can particularly think of its inhibitory effect on 5-lipoxygenase, an enzyme involved in the metabolism of arachidonic acid. This latter increases the production of cyclooxygenases COX-1 and COX-2, molecules that catalyze the formation of prostaglandins. Prostaglandins are the pro-inflammatory compounds responsible for redness and itching, especially observed in cases of eczema.

• Antibacterial.

  The nettle extract also contributes to the regulation of microorganism populations living on our skin. It particularly has a inhibitory effect on the growth of Cutibacterium acnes, the bacteria associated with acne. The nettle extract can thus be used to reduce imperfections.

• Antioxidant.

  The nettle extract contains several antioxidant molecules that, through an electron donation, are capable of neutralizing free radicals before they can damage cells and DNA. Let's remember that free radicals are particularly generated following exposure to UV rays, pollution, tobacco... and can lead to pigmentation disorders, melanomas, or premature skin aging.

• Prevention of skin aging.

  In addition to its antioxidant properties, nettle extract has a collagenase and elastase inhibitory effect. These are enzymes that degrade collagen and elastin, fibers in the dermis that ensure skin flexibility and elasticity. Thus, nettle extract helps to delay skin sagging.

• Anti-dandruff.

  It has also been demonstrated that nettle extract can help eliminate dandruff. Dandruff is multifactorial and can result from conditions such as hyperseborrhea or colonization by fungi Malassezia. In addition to being sebum-regulating, nettle extract has antifungal activity against these parasites. It is therefore often included in the composition of anti-dandruff shampoos.

• Prevention of hair loss.

  Finally, studies have highlighted that nettle extract is capable of preventing hair loss. This property is explained by its inhibitory action on 5-α-reductase, the enzyme responsible for the conversion of testosterone into dihydrotestosterone (DHT). DHT intensifies the activity of interleukin-6 (IL-6), cytokines that speed up the transition between the growth and rest phases of hair. Thus, DHT more rapidly induces hair follicles into the telogen phase, or hair shedding phase. By inhibiting 5-α-reductase, nettle thus protects hair from hormonal fluctuations or genetic predispositions leading to an increased production of DHT and consequently to hair loss.

Unlike the nettle leaf, thenettle extract found in cosmetic products is a non-irritating ingredient. It can be used by the entire family, including pregnant women and children over three years old. However, nettle extract can sometimes be slightly drying depending on the individual. This side effect is not always present but is occasionally observed. It also depends on the other ingredients present in the skincare formula. Moreover, some people may be allergic to nettle extract. Applying this ingredient to their skin can cause temporary redness and itching.

That's why we recommend performing a tolerance test before applying a skincare product containing nettle extract if you've never used it before. This will allow you to ensure that your skin is not allergic to this ingredient. To do this, apply a small amount of the product to a small area of your face, the inside of your elbow, or behind your ear. If you notice no adverse reaction within the following 24 hours, it means your skin tolerates the nettle well.

At Typology, we have formulated a purifying mask based on nettle extract, green clay and pine charcoal, sebum-regulating agents that are favored by oily skin types. Composed of 99% natural ingredients, this treatment dries out blemishes and tightens pores for healthier skin. Its clay-like texture leaves the skin soft and comfortable. Our mask should be applied once or twice a week on cleansed skin and left on the face for about fifteen minutes before rinsing.

• HANO C. & al. Nettle (Urtica dioica L.) as a source of antioxidant and anti-aging phytochemicals for cosmetic applications. Comptes-Rendus Chimie (2016).

• SEMALTY A. & al. A Comprehensive Review on Phytochemistry and Pharmacological Effects of Stinging Nettle (Urtica dioica). Current traditional medicine (2017).

• KILIC S. & al. Efficacy of two plant extracts against acne vulgaris: Initial results of microbiological tests and cell culture studies. Journal of cosmetic dermatology (2018).

• TURKOGLU M. & al. A proprietary herbal extract against hair loss in androgenetic alopecia and telogen effluvium: a placebo-controlled, single-blind, clinicalinstrumental study. Acta Dermatovenerologica (2018).