The job is to leave the shop with two packs, not a basket. One hydrocolloid box for a spot that already has fluid. One microdart box for a bump that is still closed. Skip the rest until those two have earned a place in the cupboard.
Hydrocolloid is the cheap round disc, roughly 15–40p a patch. It collects fluid from a whitehead, an open spot, or anything already weeping. Microdart is a small patch of dissolving cones, typically £0.60–£2.50+ each, for a closed early bump. They are not two strengths of the same sticker. If the spot is deep, painful, cystic, or it keeps returning in the same place, skip both and see a GP. A patch sits on the surface. It is not a cure.
The hydrocolloid vs microdart comparison is the short fork. This page is the first shopping list.
Start with one hydrocolloid box
You need a plain sticky disc. A second brand of the same disc does not add a new job.
COSRX Master Patch (Amazon UK) is a practical first box: a 24-patch mixed-size sheet, often listed around £5.99. You get smaller dots for a tight crease and larger discs when the spot needs a rim of clean skin. Superdrug is the other named path. Check the price on the day.
Mighty Patch Original does the same job in one everyday size, usually a 36-pack. It is the pack you are more likely to pick up at Boots. The site lists it around £10–12, with Boots often nearer £8.79 / 36. Hero UK and Tesco stock it too. If that single size already covers your spots and you are standing in Boots, buy Mighty Patch and leave COSRX. Do not buy both to see which works. Divide either box and you are still inside the 15–40p band. Stockist notes are on where to buy hydrocolloid patches.
Too small a disc and the edge sits on the fluid. Too large and you fight a crease you did not need. Mixed sizes help if your spots are not one diameter. One size is fine if you already know it fits.
Add one microdart box, and only for closed bumps
A hydrocolloid disc on a closed bump can stay on all night and still look unused. There was no surface fluid to collect. That is what the second pack is for.
Skin Choice Classic Darts (Amazon UK) is a plain first microdart: dissolving cones for one closed early bump. Holland & Barrett stocks the same range. The site lists the pack around £10.99. Each cone costs more than a 15–40p disc, so check the retailer before you add a spare.
Put a cone on a bump that is still under the skin. No whitehead, no broken surface, no leak. Do not put it on an open or weeping spot to push harder. That remains the hydrocolloid job. Do not judge a cone by whether the patch turns white. A cloudy centre means a hydrocolloid disc collected fluid. The white-centre guide is that colour read.
Revolution Super Dart is cones on a hydrocolloid base — a hybrid, not a straight second format. A first kit does not need Super Dart as well as Skin Choice, and it is not a reason to skip the cheap disc. The Super Dart explainer is there for later. Other stockists, including ACROPASS, are on where to buy microdart patches.
Leave these on the shelf
Under-eye ovals and smile-line crescents are a different format. They are cut for a line, not a single spot on the chin, and they cost pounds a wear rather than pence. They do not belong in a first spot-patch kit.
A star-shaped or dotted disc is still hydrocolloid if the middle is a plain sticky dressing. The outline does not collect more fluid. Wait until a round disc already does the job.
Wording such as salicylic or “active” on the box is not a third format. Decide hydrocolloid or microdart from the spot in the mirror. The extra line does not swap those jobs.
Two boxes also do not cover a deep, sore, or repeating spot. That is a GP visit, not another format in the basket.
Which pack you open tonight
Match the patch to this spot, not to last month’s.
Whitehead, broken surface, or anything weeping: hydrocolloid. Wash, then wait until the skin is dry. Leave moisturiser, oil, serum, and SPF off that exact patch. Press the rim, not just the middle. Leave it on for six to twelve hours, or overnight. The overnight apply guide is the hold checklist.
Closed and early: one microdart on that bump. Do not lay a hydrocolloid on top the same night. You have already used the dearer patch.
If the disc stayed on, stayed clear, and the bump was closed, switch format next time. A thicker hydrocolloid will not invent fluid. The unchanged-bump guide is that morning’s read. If you have already picked the spot, a hydrocolloid can cover what is open. It cannot undo the pick.
Where to buy in the UK
Two links cover a first kit. COSRX Master Patch (Amazon UK) is the hydrocolloid half: a 24-patch mixed-size sheet, often around £5.99, with Superdrug as the other named path. Skin Choice Classic Darts (Amazon UK) is the microdart half, also at Holland & Barrett, listed around £10.99. Check both retailers. Everyday discs stay roughly 15–40p each. Cones sit nearer £0.60–£2.50+ each.
If you are in Boots and only need the hydrocolloid half today, Mighty Patch Original is the pack already on that shelf. Full lists live on where to buy hydrocolloid patches and where to buy microdart patches.
Further reads are in all guides. If you are still choosing a format rather than a first box, start with hydrocolloid vs microdart.