Congested skin tends to repeat itself. Clear for a week, then the same blackheads and small bumps reappear across the nose, chin and forehead as if nothing changed. Cleansing more often rarely fixes it, because the problem usually isn't sitting on the surface. It's oil and dead skin cells trapped inside the pore itself. Medisco AC BHA Skin Booster, part of our range of Korean skin boosters, was formulated for exactly this kind of congestion, pairing a high strength BHA and AHA complex with barrier calming actives so it can get to work without leaving skin stripped or reactive.
What is actually causing the congestion
Blackheads and closed comedones form the same way. Sebum mixes with dead skin cells inside a pore, the mixture cannot shed properly and it builds up, widening the pore and eventually oxidising at the surface to form the visible dark tip of a blackhead. Skin that runs oily produces more of this mixture in the first place, which is why the same areas, usually the nose, chin and forehead, tend to congest again and again. Surface cleansing only ever reaches the top of the pore. Clearing what has built up further down needs an ingredient that can actually get in there.
Why BHA specifically
Beta hydroxy acid, or salicylic acid, is oil soluble, unlike AHAs such as glycolic and lactic acid which are water soluble. That single property matters here because sebum is oil, so BHA can travel into the pore lining itself rather than only working across the skin's surface. Once inside, it loosens the bonds holding dead skin cells together, allowing the trapped mixture to clear and helping to prevent the same pore congesting again. A peer reviewed review of over the counter acne treatments notes that salicylic acid works by breaking down the bonds between skin cells rather than acting as a true exfoliant and cites a twelve week trial in which a 0.5 percent salicylic acid treatment reduced both inflammatory breakouts and open comedones, the clinical term for blackheads, compared with an inactive control.
What is actually in AC BHA
AC BHA is formulated with a high concentration of AHA (10,080 PPM, from lactic and glycolic acid) alongside BHA (1,900 PPM, salicylic acid) to exfoliate at both the surface and inside the pore. LHA, or capryloyl salicylic acid, adds a gentler layer of exfoliation on top with less potential for irritation. Because a serum this active could easily tip into irritation on its own, it is balanced with CICA BIOTICS (5,000 PPM), a Centella Asiatica probiotic complex that supports the skin's microbiome and calms redness, along with panthenol (3,500 PPM) and allantoin (500 PPM) to strengthen the skin barrier. The result is a formula built to exfoliate congestion without undoing the skin's ability to stay comfortable while it does.
How to use it with microneedling
AC BHA is formulated as a microneedling booster rather than an everyday leave on serum and is not intended for use without microneedling, though it can be applied topically between sessions as part of a normal routine. Application depends on the depth. At 0.25mm, it is used as the glide serum during the pass itself, so the active ingredients travel through the temporary microchannels microneedling creates. At 0.5mm, apply it afterwards, once the pass is complete, onto freshly opened skin. If you are new to microneedling, a derma roller is a more affordable way to start before investing in a motorised pen such as the Dr. Pen M8S dermapen, which offers more control over depth and speed. Whichever tool you use, standard depth Dr. Pen microneedling sessions should be spaced every four to six weeks, to give the skin proper recovery time between treatments. Our full guide to microneedling at home covers hygiene, technique and aftercare in more detail. Our guide to what to apply after microneedling covers how AC BHA fits alongside the rest of the Korean skin booster range.
Who it suits and who should wait
AC BHA is best suited to oily or congested skin, breakout prone or blemish prone skin and anyone dealing with visible blackheads, enlarged pores or rough, uneven texture. It is not recommended for use on eczema, dermatitis or psoriasis, or on skin that is broken, bleeding or actively inflamed. A patch test is worth doing before full use, particularly if your skin reacts easily. Because AHA and BHA can increase skin's sensitivity to sunlight, daily SPF is essential while using this serum, not optional. This product is not intended to diagnose, treat, cure or prevent any medical condition. Anyone unsure whether it suits their skin should speak to a licensed skincare professional before starting.
Common questions
Does BHA actually help with blackheads and congested skin?
The evidence supports it. BHA's oil soluble structure allows it to work inside the pore rather than only on the surface. Clinical research has shown salicylic acid can help reduce the appearance of open comedones and congestion over consistent use. Results build gradually rather than overnight and are supported by keeping the rest of your routine non comedogenic.
Can I use AC BHA without microneedling?
It is formulated primarily as a microneedling booster and is not recommended as a standalone daily serum. It can be applied topically between microneedling sessions as part of a normal routine, but its main purpose is to be used during or immediately after a microneedling pass.
How often should I use it?
Frequency follows your microneedling schedule rather than a separate routine. Standard depth Dr. Pen sessions should be spaced every four to six weeks to allow skin to recover fully between treatments. Check the product page for your specific derma roller or dermapen for guidance on depth.
Is AC BHA suitable for sensitive skin?
It contains barrier supporting ingredients like CICA BIOTICS, panthenol and allantoin to help offset the strength of the acids, but it is still a high concentration exfoliating formula. Patch test first, avoid it on broken or actively inflamed skin and if your skin is reactive or you are unsure, check with a skincare professional before adding it to a microneedling routine.
If congestion and blackheads keep resurfacing no matter how carefully you cleanse, AC BHA may be worth adding to your next microneedling session. You can find the full Medisco AC BHA Skin Booster at Pure Derma London. If you are not sure which depth or device suits your skin, our team is happy to help. Just email help@purederma.co.uk and we will point you in the right direction.
