Sulfur, a solution for acne-prone skin?

Acne is a complex skin issue, influenced by factors such as hormones, genetics, and lifestyle. It is the most commonly encountered condition in outpatient clinical practice, accounting for approximately 9% of dermatologist consultations in 2022 in France. In comparison, eczematous dermatoses, psoriasis, and skin cancer accounted for 3.7%, 3.5%, and 0.2% of consultations, respectively.

From non-inflamed comedones to inflamed papules, pustules, cysts, and nodules... there are several reasons why pimples can develop, and they often combine.

• One of these reasons is the presence of bacteria responsible for acne. Although there are many strains of bacteria that cause acne (Staphylococcus epidermidis and Staphylococcus aureus), the most common is Cutibacterium acnes (formerly Propionibacterium acnes). These bacteria are naturally part of the skin microbiota, but touching your face can introduce more of these bacteria than usual. They then penetrate the pores and their multiplication causes inflammation (redness, swelling, pus). It is this irritation that can give pimples a red and irritable appearance.

• Theexcess sebumis the primary cause leading to the appearance of skin imperfections. The hyperactivity of the sebaceous glands is a characteristic of oily skin, which can lead to several problems. Firstly, the accumulation of sebum in the pores can mix with other impurities and create hard "plugs" that further irritate the pore. These "plugs" are the origin of whiteheads and blackheads. Secondly, the bacteria responsible for acne feed on sebum. Therefore, the more sebum there is on the skin or in the pores, the more these bacteria can feed and multiply. Excess sebum can significantly contribute to the occurrence of skin breakouts.

• Theaccumulation of dead skin cells is one of the potential factors that could be causing your breakouts. Your skin is constantly shedding dead cells and replacing them with new ones during the process of cellular renewal. Typically, youthful skin completely renews itself every 28 days. Most of these dead cells naturally flake off, but some remain and accumulate on the skin's surface. They can also penetrate into the pores and contribute to the formation of hard "plugs" that cause whiteheads and blackheads.

It has been reported that sulfur is more effective against mild to moderate inflammatory acne and comedonal acne. Therefore, if you have red pimples, blackheads, whiteheads, or a combination of the three, sulfur can improve the appearance of your skin due to the numerous benefits it can provide. However, it is less effective in cases of moderate to severe forms of acne or cystic outbreaks, especially when used as a standalone treatment.

• Absorbs Sebum: Sulfur aids in the absorption of excess sebum, a source of acne, by drying out blemishes and freeing clogged pores.

• Neutralizes bacteria: When applied to the skin, sulfur is transformed into hydrogen sulfide (H2S) through the action of three enzymes present in the skin (cystathionine-γ-lyase, cystathionine-β-synthase, and 3-mercaptopyruvate sulfurtransferase). This compound has a lethal effect on bacteria, including Propionibacterium acnes, thus preventing the spread of bacteria responsible for acne and causing irritations. Research also shows that sulfur is an effective treatment option for controlling vulgar acne caused by the bacterium Staphylococcus. It also kills fungi and other parasites.

• Exfoliates the skin: It has been demonstrated that sulfur has keratolytic effects, which means it aids the skin in shedding dead cells, thereby enhancing the renewal of skin cells. This property thus helps to prevent the clogging of pores (the precursor to a breakout) from developing.

• Calms inflammatory reactions: Studies have shown that sulfur affects the permeability of the cell membrane in tissue affected by pain. The action of this mineral enhances the effects of the body's pain-relieving hormones to alleviate inflammation.

Whether you're using it as a facial mask once or twice a week for prevention, or as a localized treatment to soothe stubborn pimples, sulfur appears to be a quadruple threat to acne. Several clinical studies demonstrate its effectiveness on mild to moderate acne with a significant reduction in the number of inflammatory lesions and comedonal lesions, with an improvement generally observed after 4 to 6 weeks of daily use.

However, the evidence is insufficient regarding its sole effectiveness on acne. Although sulfur-based treatments could potentially be useful on their own, sulfur is often combined with other topical agents, such as benzoyl peroxide, thesalicylic acid, sodium sulfacetamide, or alpha-hydroxy acids (AHA) which have the same anti-inflammatory and keratolytic properties as sulfur. Combined, they have a synergistic effect to enhance their effectiveness in treating acne. Therefore, additional studies are needed to evaluate the effectiveness of sulfur for this use.

Sulfur against acne scars?

Sulfur is not a treatment for acne scars. There are more effective options available to promote wound healing and reduce the post-inflammatory hyperpigmentation, or professional treatments such as microdermabrasion and fillers. That being said, sulfur can provide some improvements to the skin due to its exfoliating effects to even out the skin and lighten brown spots, which may remain once an inflamed lesion heals.

• CRAIG G. E. & al. Benzoyl peroxide and sulfur: foundation for acne management. Canadian Medical Association Journal (1966).

• KLIGMAN A. M. & al. Is sulphur helpful or harmful in acne vulgaris? British Journal of Dermatology (1972).

• CARTER D. & al. Sulfur revisited. Journal of the American Academy of Dermatology (1988).

• NICOL K. & al. The use of sulfur in dermatology. Journal of Drugs in Dermatology (2004).

• DEL ROSSO J. Q. The use of sodium sulfacetamide 10%-sulfur 5% emollient foam in the treatment of acne vulgaris. Journal of Clinical and Aesthetic Dermatology (2009).

• BROWN J. N. & al. Treatment of Demodex-associated inflammatory skin conditions: A systematic review. Dermatologic Therapy (2019).