Introduction
Clearstem has quietly built a cult following among ingredient sleuths who want science backed formulas without the drama, yet it is still under the radar for anyone whose skin care routine tops out at cleanser and SPF. If you have heard of the brand you probably associate it with breakout friendly actives and a no nonsense approach to formulation, and that reputation set my expectations high.
Enter Sulfur Spot&Mask, a name that sounds like the world’s shortest to do list: spot, mask, done. Clearstem calls it a weekly acne clearing mask that dives into pores to zap oil, whiteheads and bacteria in minutes, powered by a quartet of clay, zinc, sulfur and glycolic acid that supposedly act like action heroes on congested skin. They position it as a two for one deal: slap it on a blemish overnight or paint it across your whole face once a week to stay ahead of breakouts.
To see if those promises hold up in the real world I spent two full weeks working Sulfur Spot&Mask into my routine, tracking texture, redness and those determined little under–the–surface bumps. Here is how it fared and whether it deserves a spot on your shelf.
What is Sulfur Spot&Mask?
Sulfur Spot&Mask is a wash-off treatment that sits in the same family as clay masks you rinse away after a short contact time. Products in this category work by depositing active ingredients on the skin for several minutes then getting removed before they can over-dry or irritate. The rinse step helps prevent potential residue that might otherwise clog pores or interfere with other steps in a routine.
This particular formula is positioned as both a weekly all-over mask and a targeted spot treatment. It relies on 5% sulfur to dry out existing blemishes, kaolin clay to absorb excess oil, glycolic and lactic acids to nudge along surface exfoliation and zinc oxide for additional calming support. Clearstem advises applying a thin layer to clean skin, leaving it on for about ten minutes, then rinsing and following with the rest of your regimen. The blend aims to reduce whiteheads and blackheads while discouraging new breakouts when used consistently once a week.
In short, Sulfur Spot&Mask is a short-contact leave-on then rinse-off product designed to deliver a concentrated burst of oil control and gentle exfoliation without staying on the skin all night, making it an option for those who find overnight acne creams too harsh.
Did it work?
In the name of very scientific research I benched my usual wash-off mask for a few days before starting this trial, giving Sulfur Spot&Mask sole custody of my pores for a full 14 days. Two weeks feels like a reasonable window to see whether a weekly treatment can actually move the needle on congestion and oil.
I used it three ways. First evening: a thin all-over layer for the recommended ten minutes. There was a faint medicinal scent and a mild prickly warmth around my nose but nothing dramatic. After rinsing my skin felt smoother and notably matte though not tight. Over the next two nights I dabbed it on two budding whiteheads. By morning each had flattened to the point that concealer went on without that annoying bump. Encouraging start.
Day seven saw round two of the full-face application. This time I noticed a bit of flaking around my mouth 24 hours later, likely the combined punch of sulfur plus glycolic. A drop of moisturizer solved it but it did remind me the formula is more assertive than the marketing fluff suggests. On the upside my forehead, usually a parade of micro-clogged pores, looked clearer and felt smoother to the touch.
During the final stretch I stuck to spot treating only. A hormonal chin cyst still pushed through despite my optimism, proving the mask is better at handling surface-level drama than deep underground rebellions. Smaller blemishes continued to shrink faster than they do with salicylic acid alone, yet overall redness stayed about the same.
So did it deliver? Mostly. It lived up to its promise of drying out whiteheads quickly and tamping down excess oil after each use, but it did not transform my skin or prevent every new blemish. For that reason I will not be giving it a permanent place in my routine, though I would happily keep a mini size on standby for emergency spot duty. If your breakouts hover at the whitehead and blackhead stage you may find it more indispensable than I did.
Main ingredients explained
Sulfur takes the lead at 5 percent and is the reason the mask smells faintly like hot springs. In that concentration it works as a keratolytic, meaning it softens the bond between dead cells so they shed more easily while simultaneously creating an environment that acne bacteria hate. Because sulfur can be drying it is paired with kaolin and bentonite clays that vacuum up excess oil without stripping all moisture. The clays give the mask its quick mattifying talent and rinse away clean to avoid leftover grit.
Next come the chemical exfoliants. Glycolic acid, the smallest alpha hydroxy acid, slips into the top layers of skin to dissolve the glue between cells which encourages smoother texture and helps any post breakout blotches fade a touch faster. Lactic acid tags along at a lower percentage adding mild exfoliation plus water binding properties that help offset the dryness sulfur can cause. If your barrier is temperamental you may notice a brief tingle yet both acids are washed off after ten minutes so irritation risk stays low for most users.
Zinc oxide rounds out the core quartet with calming and mild antibacterial benefits. It is the same mineral used in sunscreens but here it is functioning as a soothing agent that can take down redness after you rinse. Niacinamide, aloe juice and sodium PCA add extra support by reinforcing the skin barrier and holding moisture. You will also find cannabis sativa seed oil and tocopheryl acetate (vitamin E) which contribute lightweight emollients to keep flaking at bay.
A quick note on pore friendliness: the formula does contain caprylic/capric triglyceride and cetyl alcohol, both rated in the mid range on some comedogenic scales. That means they could clog pores for people who are extremely sensitive to such ingredients. Comedogenic simply means an ingredient has the potential to block pores and trigger breakouts though it often depends on the overall formula and individual skin. In my testing I did not notice congestion from these emollients but very acne prone readers should keep the possibility in mind.
Clearstem confirms the blend is vegan and cruelty free, so no animal derived materials sneak into your routine. As for pregnancy safety, the actives here are generally considered low risk yet essential oils like lavender plus resurfacing acids can be controversial while expecting. The safest move is to run the full ingredient list by a medical professional before use if you are pregnant or breastfeeding.
Finally there are no added fragrances beyond the natural scent of its plant oils and sulfur so the aroma dissipates quickly once rinsed. The pH sits in a mildly acidic range that allows the AHAs to do their job without upsetting the skin’s own acid mantle. In short the ingredient deck is thoughtful and fairly short by modern mask standards, balancing oil absorbing power with just enough hydration to keep you from looking like a desert after every use.
What I liked/didn’t like
Here is the quick rundown.
What works well:
- Dual use as weekly mask or spot treatment makes it easy to slot into most routines
- Visibly flattens whiteheads and cuts surface oil within a single use
- Short contact time rinses clean so it is less likely to over strip or clash with leave-on actives
- Thoughtful mix of sulfur, AHAs, zinc and calming extras balances exfoliation with barrier care
- Vegan formula with no added fragrance suits those avoiding common irritants
What to consider:
- Natural sulfur scent is noticeable even during the brief wear time
- May cause mild flaking on dry areas unless you follow with a richer moisturizer
- Helps surface blemishes but offers limited support for deeper cystic breakouts
My final thoughts
After two weeks of consistent use I can say Sulfur Spot&Mask sits comfortably in the “good but not quite game changing” category. It nails the basics of a wash off treatment: delivers a swift hit of oil absorption, nudges pores toward clarity and rinses without leaving that dreaded tight film. For my combination skin its 10 minute ritual was a welcome middle ground between gentle clay options that do little and hardcore acid peels that can leave me pink for days. Still, its reach stops at surface-level drama; deeper cysts had no intention of listening. With that in mind I am stamping it with a solid 7/10. I would recommend it to a friend who battles frequent whiteheads or wants a once weekly reset but I would pair that recommendation with a reminder to keep expectations realistic.
Who will love it? Oily to normal skins that break out in predictable T-zone flare ups and appreciate a quick routine. Who might pass? Anyone dry, sensitive or chronically cystic who needs heavier anti-inflammatory artillery. I have rotated through more masks than I can remember and approached this one with that context so I feel the verdict is fair.
If sulfur is not your scent or you just enjoy variety there are a few alternatives I reach for often. Pink Clay Glow Mask by Deascal is an excellent all-rounder that exfoliates, clears pores, brightens and somehow suits every skin type while staying friendly on the wallet. Rare Earth Deep Pore Cleansing Masque by Kiehl’s leans into kaolin and bentonite for a deeper vacuum effect on oilier days. Resurfacing Mask by Tata Harper gives a gentle enzymatic polish when texture is the main concern. Finally Salicylic Acid 2% Masque by The Ordinary is a fuss free option when blackheads dominate the conversation. I have used all of these enough to trust their results and they each fill a slightly different need.
Before you add anything new, remember the basics: patch test on a small area first, especially with sulfur and acids in the mix. Sorry for sounding like an over-protective parent but your face will thank you. And keep in mind that clarity maintained by any mask is temporary without ongoing care, as if that were not obvious.