How Benzoyl Peroxide Steals Your Skin’s Antioxidants

Since 20 years ago, many of the deadliest acne villains are finally having the spotlight shined on them.

Sugar consumption is now called a public health crisis, the pesticide atrazine is now restricted after being washed into rivers and making frogs infertile. Even the former acne staple of antibiotics are now viewed with suspicion, even by mainstream dermatologists, after bacteria evolved and gained resistance.

But other villains remain just as popular as ever. Accutane is actually regaining popularity as its side effects were successfully dismissed as scare stories (they’re not). In particular, benzoyl peroxide is still considered to be a well-controlled dermatology staple.

The best you’ll hear is “may cause minor irritation or burning”. It makes sense, because there’s nothing nearly as eye catching as your teeth dropping out from sugar or your arteries clogging from trans-fats.

Benzoyl peroxide undeniably does work for acne, but the problem is what comes after. When the safety buffer of benzoyl peroxide is removed after several months, your skin will be in a much worse equilibrium. Its long term damage will quickly become apparent, with new pimples…

…and in particular, there’s one subtle but significant danger that could scupper all your hard earned acne progress. Benzoyl peroxide depletes the antioxidants in your skin, possibly after just 1 application. 

 

Bad for antioxidants by its very nature

It all started with a 1998 study, conducted on humans, where benzoyl peroxide decreased the skin’s vitamin E by 95% and its vitamin C by 70%. That’s a gigantic decrease, and the flaw is integral to the very nature of BP.

Essentially, p.acnes bacteria hides away in your skin pores because it dislikes oxygen. It is an anaerobic species, and when BP is applied to the skin, it splits into its constituent parts of benzoic acid and oxygen. The oxygen spreads from the application zone like a tidalwave, washing into the p.acnes at high speed and making them less able to exist. That’s how it clears acne so effectively, but this oxygen also acts as a “reactive oxygen species” AKA a free radical.

The benzoic acid portion also acts as a free radical, by breaking down into benzoyloxy and then benzyl radicals. These improve acne further by attacking the dead skin cells clogging pores, weakening their hold, until they’re washed away by oil and sweat. They also attack white blood cells, which sounds disturbingly close to HIV, but actually explains BP’s anti-inflammatory properties, because it only happens locally on the skin.

The bottom line is that benzoyl peroxide’s entire success is based on flooding your skin with free radicals, and what are those? You’re probably well familiar with them – they’re unstable molecules lacking an electron, which are compelled to steal a new electron from healthy, intact cells to restore their stability. Free radicals damage your eyes, brain and lungs, and BP can create chains of them on the skin.

We covered all this in the old benzoyl peroxide article from 2014. Specifically, we warned that the squalene in your sebum (oil) would be oxidised by free radicals and mutate into squalene peroxide, the single most pore-clogging substance on earth. Squalene peroxide increases dead skin turnover and oil production, and free radicals are also specialists in dulling skin cells – just look at proud smokers of 30 years.

But the other threat of free radicals is snatching antioxidants. Your skin stockpiles antioxidants as a direct armour against free radicals. That’s what they exist for, so we’d know that BP decreases antioxidants even without studies, but here’s some anyway…

 

The evidence bank

We already have the 1998 affair, and this 2001 study also tested living humans. After supplementation with alpha tocopherol, the most popular supplemental form of vitamin E, lipid peroxide formation from benzoyl peroxide fell significantly. Lipid peroxides are fat soluble free-radicals, which roam around fatty tissues like cell membranes and oils.

11 volunteers took vitamin E for 7 days, and started a BP course on day 8. This reveals a great strategy in itself, taking vitamin E while using BP, but here’s the real point: it shows how benzoyl peroxide can deplete your stocks. Antioxidants deactivate free radicals by donating an electron, but afterwards, their antioxidant powers are lost, unless a molecule like glutathione comes along and regenerates them.

Plus, some patients didn’t take vitamin E, and their skin levels declined by 93.8% after using BP! That’s another gigantic figure. I would advise you to run a mile from benzoyl peroxide based off this one study alone. It’s surprising how closely it matches the 1998 figure of 95%. As a side point, vitamin E didn’t counteract the skin barrier damage from BP.

This 2001 study took it a step further. Firstly, the “45 year acne staple” was applied to human keratinocytes, the standard building block cells of the epidermidis.

This quote says it all: “about 50% of the cellular vitamin E was depleted within the first 30 min“.

This was isolated cells, so living human skin will doubtlessly be more resistant, but it’s still a grim figure. This time, the main self-manufactured antioxidant glutathione was also tested, and the ratio of oxidised glutathione (useless) to intact glutathione increased sharply. Meanwhile, BP didn’t increase the inflammatory chemicals NFKappa-B or interleukin-8, although interleukin-1beta did rise. Benzoyl peroxide has its specialities – draining antioxidants.

Scientists are getting seriously worried. This 2010 review summarised the plentiful evidence, and commented that vitamin E’s “near elimination by BP should be, at the very least, cause for concern“. They advised pharmaceutical companies to combine benzoyl peroxide with vitamin E in the future, as a buffer. 10 years have passed, however, and BP is still king of the acne castle, with accutane and antibiotics being its trusted palace servants.

 

BP crushes several antioxidants

The vitamin C reduction of 70% hasn’t been repeated, but that’s only because no other studies exist.

Glutathione has another study though. It was mainly testing fresh spearmint leaves as a benzoyl peroxide shield, but firstly, they tested BP’s damage, and three glutathione forms plummeted in the skin: glutathione peroxidase, glutathione-s-transferase, and glutathione reductase. Catalase also fell, another self-manufactured antioxidant.

Theoretically, benzoyl peroxide could interfere with the enzymes that originally manufacture both glutathione and catalase, but it’s probably identical to vitamin E – a blunt force depletion by generating masses of free radicals. Out of pure interest, spearmint leaves did defend against BP.

Vitamin E and vitamin C are rightfully popular, in oil and serum form, but glutathione is a highly underestimated antioxidant for acne. This study found 20% lower amounts in acne prone skin, and BP can push you deeper into the pits. 

Additionally, supplementing human cells with N-acetyl-cysteine decreased the free radical (reactive oxygen species) damage (2004 study). The connection? NAC is the most rapidly acting supplement in existence for increasing bloodstream glutathione levels. Doctors keep it in their drawers for treating emergency painkiller and alcohol overdoses; it acts within minutes. If NAC helps, then that clearly illustrates how BP dabbles in the antioxidant-depleting arena.

 

The dangers

By crippling vitamin E and vitamin C, benzoyl peroxide can not only create squalene peroxide, but also lower your defences against all other free radical threats. That includes air pollution, smoking, later doses of BP, VOCs from deodorant, fumes from frying with non-stick cookware.

You’ll also lose their normal skincare powers, which include sun protection for vitamin E, and collagen formation for vitamin C. Collagen is the youth protein that makes skin sturdy, and accumulates rapidly in healing wounds (and pimples). I advise all acne patients to focus on vitamin E and vitamin C, optimising your diet, and taking a natural, additive free supplement if necessary. The ratio of vitamin E in your face to your upper arm is 20:1.

Additionally, if smaller plant antioxidants like flavanols and anthocyanins are destroyed (berries, cruciferous vegetables), then you’ll lose the subtle glow and pigment they provide.

BP really could erase months of hard work and patience in one fell swoop. Normally, vitamin C rises in the bloodstream instantly after swallowing an orange whole, but with the skin it’s different. Vitamin C must accumulate slowly in its layers, in the very core of skin cells themselves, as part of the tissue. Vitamin E is identical.

These aren’t side dangers that can be softened, not like lavender oil and its minor irritation (cool and dark storage is the key). Unleashing free radicals is the core of the benzoyl peroxide program. It’s integral to how it works. You can’t avoid it. The power that clears acne is the same one that depletes your precious vitamins. 

Some websites recommend benzoyl peroxide and vitamin E for acne in the very same article! They don’t notice the contradiction they’re falling into.

 

A great illustration

Back in the real world, rather than eternally trapped in the pages of scientific journals, there’s a big debate over whether to combine benzoyl peroxide with tretinoin.

That’s a topical retinoid, synthetic vitamin A, designed to reduce the sebaceous glands’ oil production. It’s another common pharmaceutical prescription, but many dermatologists believe that benzoyl peroxide destroys the tretinoin molecule, rendering it inactive. Indeed, one study found an 80% reduction when tretinoin was packaged in cream form.

Consequently, dermatologists are advising their patients to apply them at different times; one remedy in the morning and one remedy at night.

Scientists have been forced to innovate, and the newfangled tretinoin forms are packed in a stabler microsphere cream. Essentially, the tretinoin molecules are contained in numerous tiny macrosponges, measuring 10um to 25um across, which only release after PH, temperature, and humidity changes in response to rubbing.

Studies have found this new tretinoin to be immune to BP, but the fact that it’s necessary is a clear parallel to the destruction of the vitamin E molecule, or the glutathione molecule.

Benzoyl peroxide doesn’t uniformly destroy all antioxidants. For example, this study found that the red wine antioxidant resveratrol enhanced the powers of BP to kill p.acnes bacteria. Clearly then, the resveratrol had stayed intact. But vitamin E, vitamin C and glutathione are some of the most important antioxidants.

 

What will happen?

If you’ve spent months trying to build up a vitamin E armour, then some hastily applied benzoyl peroxide could burn it up within days. That’s another reason why I don’t recommend this undeniably effective brute force acne remedy.

BP works in the short term, but in the long term, the pimples typically come roaring back. People even claim on internet forums that the skin develops an addiction to BP, that it can’t cope without.

With vitamin E and vitamin C depletion, we have an explanation for this “addiction”, and here’s a possible timeline of events:

Day 1 – you dab on 5% benzoyl peroxide using a cotton bud. Propionibacterium acnes dies off en masse due to oxygen exposure.

Day 20 – your acne gets more irritated at first due to the inflammation of free radicals.

Day 40 – finally it’s working! Fewer pimples are forming, as your immune system is no longer responding to the p.acnes stimulation.

Day 50 – your older pimples have faded, and your skin is visibly clearer in the mirror. You’re very satisfied with BP.

Day 60– no further improvements, but you’re at a nice plateau of significantly clearer skin.

Day 90 – as your vitamin E declines, more pimples seem to be forming, as your defences against squalene peroxide fall. Your skin tone has also gone downhill; the golden glow has slipped away.

Day 100 – your acne remains slightly better than baseline, but in frustrated disappointment, you refuse to buy another bottle.

Day 120 – without BP suppressing them, your p.acnes colonies have now recovered. Worse, your vitamin E is still depleted. Your acne is now worse than ever!

The bottom line is that benzoyl peroxide is not a long term solution for your acne. 

 

Stay away from BP

You could argue that supplementing with vitamin E will allow you to access benzoyl peroxide’s undeniable benefits, while protecting your antioxidant reserves.

The problem is that free radical threats are everywhere – air pollution, second hand cigarette smoke, fumes from frying with non-stick cookware. The vitamin E in your skin is already under great pressure.

Topical retinoids are the only popular pharmaceutical acne remedy without severe side effects, and also salicylic acid. The main three aren’t identical though. Accutane clears acne over the long term, but has horrific side effects like infertility, IBS and hair loss. Benzoyl peroxide doesn’t wreck your health (unless the skin cancer theories are accurate) but can make your acne situation worse in the long run. Poor old antibiotics wreck your gut bacteria and no longer work for acne properly. There are many roads to pharmaceutical failure.

 

Rebuttals from skincare companies

Among normal acne patients, the worries about benzoyl peroxide’s safety are gaining serious steam.

Users have been warned by friends of ageing and premature wrinkles, others worry about cancer, and teenagers and adults alike complain of reduced sunlight resistance. It sounds suspicious almost immediately – a topical treatment which works by unleashing free radicals. They have a serious marketing problem compared to cleansing vitamin C serums or natural aloe vera gel squeezed from a desert shrub.

Consequently, many skincare companies are now issuing FAQs about benzoyl peroxide on their facebook pages or websites. They’ll insist that benzoyl peroxide creates only short-lived chains of antioxidants, which destroys p.acnes, but fizzle out before they can oxidise deeper skin tissues. They’ll say that BP breaks down into safer phenyl radicals, rather than the hydroxyl radicals of hydrogen peroxide.

Some of these arguments are true, but the studies above speak for themselves: a 50-95% fall in vitamin E.

Short-lasting or not, phenyl radicals or not, the skin’s antioxidants were crippled. Many were conducted on living human, not just cells.

In the facebook comment sections, users are commonly reassured about benzoyl peroxide and thank the authors, but personally, I’d advise you to stay paranoid. Skincare companies also recommend combining BP with a topical antioxidant, but a 95% fall won’t be reversed by dabbing on a cotton puff. Some FAQs even claim that benzoyl peroxide is no more damaging than your skin being surrounded by oxygen 24/7!

The only real myth seems to be that benzoyl peroxide causes cancer. 

 

Not uniformly evil

As ever, there’s one twist in the tale, as benzoyl peroxide also has subtle free radical lowering powers.

According to this 1994 study, it inhibits neutrophils, a chemical of the immune system that naturally generates free radicals, to break down damaged tissue. They couldn’t find an explanation, as two proteins called protein kinase C and calmodulin which trigger neutrophil activity were barely altered. Inhibiting neutrophils is a great power, one we commonly watch for; it’s found in the natural remedies of lavender oil and rose water. Likewise, ever heard of lithium causing acne, the bipolar disorder medication? It really does, and firing up neutrophil production is almost certainly why.

Like anything, benzoyl peroxide isn’t a cartoon villain devoted to pure evil. So this is when we’d normally say that everything is complex, and that we’ll have to wait for real world outcomes, but we already have one: the vitamin E result shows that the balance tilts firmly into antioxidant depletion. The neutrophil-lowering powers can’t be that strong. It makes sense; the beneficial power is useful but indirect, whereas BP’s free radicals are applied straight to the skin.

 

Conclusion

You are now slightly closer to being a full-fledged expert on benzoyl peroxide.

Suffice to say, I advise you not to use it. Its antioxidant robbing powers are almost proven, but you know what else is proven? A good 10-15 natural acne remedies.

Zinc supplements were shown in a study to lower acne by 49.8%. Mangosteen has 4 acne studies showing reductions of 50-67%. Benzoyl peroxide might be off limits now, but you have plenty of natural acne remedies to experiment with, and if one fails, it’s doubtful that 10 more will.

 

Thanks for reading!