Is niacinamide or salicylic acid better for acne?
The surface of the skin is called the "acid mantle," and this generally does an excellent job of protecting the skin from damage, including sun, wind, pollution, dehydration and infection. When healthy, it also inhibits the growth of bacteria and fungi. So it is important to look after it as it is the best defence for most skin problems, including acne.
Niacinamide or Salicylic acid?
Niacinamide’s effectiveness is likely due to it having anti-inflammatory properties and in being a precursor to two co-enzymes in skin cells which are vital for skin damage repair, healthy cell production and proliferation. It also helps neutralise free radicals (that can damage cells). It can also slow over-production of sebum when used regularly.
Salicylic acid also has anti-inflammatory and anti-bacterial properties and is a keratolytic, which helps prevents pores clogging. However, it must be used with care, as it can be very irritating when used above 2% in a product.
Of the two, salicylic acid (specifically at 0.5%-2%) is FDA (USA) approved for the treatment of acne (Niacinamide is approved in the treatment of pellagra, a type of dermatitis that can occur when niacin is low). I often combine Salicylic acid with Azelaic acid for spot-prone skin as this can reduce the appearance of prominent, inflamed pores.
The other ingredients approved by the FDA specifically to treat acne are Benzoyl peroxide and Sulphur (sulfur).
Benzoyl peroxide releases oxygen into the microenvironment of the acne bacteria that allow acne to proliferate - and they prefer anaerobic conditions. It is often combined with zinc and it’s effect has also been shown to be boosted when mixed with Tea-tree oil, (both at 5%). Like salicylic acid, this can be very irritating to skin, especially when used at over 2.5% - remember it is a bleach so can take the colour out of face cloths, towels, and clothing. It can also cause skin to become dry, red, inflamed and itchy.
Sulfur should just be applied to individual spots; it dries the excess oiliness on skin and the underlying pustules and does this quickly. It also changes the skin environment, helping to reduce the acne-causing bacteria. The FDA only approves use to 10%, and like the others, this can be irritating, especially in higher concentrations.
I often add zinc to formulations to help inflammation and blemishes. It is a trace element, but humans are unable to store it, so instead must get it in their diet daily. Unlike a number of vitamins and minerals in skincare products, it is the surface layers of skin that contain the most zinc, so topical use is sensible and efficient. It has anti-inflammatory and anti-bacterial properties and is very good at countering yeast infections, which often accompany acne.
Allantoin - I use this with botanical extracts as it is an excellent keratinolytic and it helps skin moisture-retention and has been found to be effective against acne.
Alpha hydroxy acids or poly hydroxy acids (AHAs and PHAs)can help. PHAs are less irritating and so are a better first choice for acne-sufferers. (Salicylic acid is a beta hydroxy acid (BHA)). These keep the dead skin cells turning over and the pores clear. They also help retain moisture in the skin which in itself should improve skin strength and tolerance. Glucono lactone (a PHA) used at 14% in a double-blind clinical study on 150 patients was significantly better than those given 5% benzoyl peroxide, and had fewer adverse side effects.
Retinoids (Vitamin A and pro-vitamin A)are regularly used to treat acne comedones and can reduce inflammatory lesions too.
Medicinal Herbs for Acne
Herbs are generally well-tolerated and often effective, especially when used in combination with other ingredients. Most hydrosols have anti-inflammatory and antibacterial activities and some have phytochemicals useful in the treatment of acne. Polyphenols are the most beneficial for acne and we use the following for a variety of skin complaints, including blemishes: resveratrol, curcumin, ellagic acid and epigallocatechin 3-gallate. The tannins and flavonoids in green tea have performed well in acne treatment trials, partly due to their antiseptic and anti-inflammatory effect.
Useful plants include: Aloe vera, Green tea, German chamomile, Calendula, Lavender, St John’s wort, Cornflower, Evening primrose, Borage, Rose, Rosemary, and Yarrow. Aloe vera was not conclusively effective, but shown to help reduce the irritation of other, more effective treatments when used together. Rosmary contains rosmarinic acid which can effectively reduce damage from oxidative stress and the essential oil has shown significant improvement to skin affected by acne.
Hemp seed oil has been shown to improve acne, rosacea and seborrhoeic dermatitis, it appears to strengthen skin, making it more resistant to bacterial and fungal infections. And Usnic acid found in lichen, inhibits the growth of P. acnes.
Finding the Cause
If acne persists, it is worth attempting to understand what is the underlying cause, rather than just treating the symptoms. The two main phases are:
Individual spots - A spot forms in a pore, where hair follicles appear (the individual hairs can be tiny and only visible under magnification). The wax/oil in the skin works its way out, by moving up the little hairs (so removing the hair shafts can make acne worse). Pores can become blocked by the sebum (the dark colour of black-heads is the result of the oil becoming oxidised when meet the air, it isn’t ‘dirt’ as such). At times, an excess amount of sebum may be produced, due to various factors including hormonal changes. If oil in the pores builds up, it can seal itself off and a little pocket will form, turning white due to localised infection (comedones). Sometime dead skin cells that stick to the surface can block the pores causing problems and hairs can grow inwards, which can also trap infection locally.
Inflammatory acne - this is more difficult to treat and often more problematic. Papules appear due to skin inflammation. This can be painful with a red or slightly raised appearance. If this area is prolific and left untreated it may become infected, white pus can form under the skin and collect in the pores. If left untreated and it worsens, the entire area may work its way deeper into the skin, forming nodules and even cysts, which often require more than topical treatment alone (antibiotics like erythromycin are often used).
Prevention is better than cure..
Soap or other products with a high pH are often too alkaline for skin, which is comfortable at a pH 4.5 - 6. Anything over pH 8 or under pH 3 can be very irritating and damage the acid mantle, making skin more susceptible to irritation and infection, including acne. There are treatments that are delivered at a low pH, necessary for the ingredients to work effectively. These can be well-tolerated - partly as the skin will return to it’s ideal pH pretty quickly, providing the solution isn’t very low (under pH3). Alkaline solutions tend to be used more often.
If skin is naturally dry, it is probably already more alkaline than average and so soaps are more likely to increase its vulnerability. Using acidic products can improve the dryness, strengthen the skin and make an outbreak less likely. Very oily skin can also be problematic and applying an alkaline soap, in an attempt to get skin ‘squeaky clean’ might seem logical, but often exacerbates the problem by triggering skin to produce more sebum.
Moisturising and Diet
Using a good moisturiser before applying a spot cream will help to limit any irritation the spot-treatment may cause and well-hydrated skin is better able to protect itself.
Most importantly - try to get the vitamins and minerals necessary for happy skin in your diet, this is especially true of Vitamins A, B (almost all the Bs are useful to skin health), C and E. Vitamin D is delivered via sunlight; some people believe this helps their acne, others believe it worsens it. Certainly any burning or inflammation is unlikely to improve the situation! Dairy products may worsen hormonal acne and I’m afraid both chocolate and alcohol are on most To Avoid lists.