Isoi up
The ISOI up collection is anchored by the Blemish Care Up Serum, available in seven sizes from 15ml to 70ml, alongside the Blemish Care Up Cream 55ml. This range is unusual in offering the same serum formula across a continuous size spectrum, making it easy to match the purchase to your routine commitment - from a 15ml trial through to the 70ml large-capacity version. The Skincare Vegan Tone Up Sun 40ml extends the line into daily SPF care.
By Skinsli editorial Updated
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Buying guide
Buying Guide: ISOI Blemish Care Up Collection
The ISOI up collection is defined by the Blemish Care Up Serum, which comes in more sizes than almost any Korean serum on the market - from 15ml through to a 70ml large-capacity version. This sizing strategy makes the collection unusually accessible: you can trial the serum at a low commitment and scale up directly without switching products. The Blemish Care Up Cream and a Vegan Tone Up Sun SPF round out the range. This guide covers what each product does, how to choose between the serum sizes, and how the line fits into a blemish-focused routine.
Blemish Care Up Serum: What It Does
The ISOI Blemish Care Up Serum is an active serum targeting blemish-prone and congested skin. The Up designation positions it as an upgraded or strengthened version of a standard blemish serum - delivering a higher or more effective active load per application. The serum applies at the treatment step after toner and before cream, addressing breakout-prone areas with concentrated blemish-care actives.
The formula is consistent across all sizes in the collection - the differences between the 15ml, 20ml, 25ml, 30ml, 35ml, 50ml, and 70ml listings are quantity only. Two variants appear alongside the size variants: the 1 Blemish Care Up Blemish Serum 50ml and the Blemish Care Up Serum Blemish Serum 70ml Large Capacity, both carrying the same formula in their respective sizes.
Choosing the Right Blemish Care Up Serum Size
The Blemish Care Up Serum's multi-size offering makes size selection straightforward if you apply the standard logic: use a small size for a first purchase and scale up when you know the formula suits your skin.
The 15ml is the minimum viable trial - approximately three to four weeks of daily use. The 20ml and 25ml extend to four to six weeks. The 30ml and 35ml reach one to two months of daily use. The 50ml provides approximately two months, and the 70ml Large Capacity covers two to three months. If blemish management is an ongoing concern and the 35ml or 50ml size already proves effective, the 70ml is the most economical per-ml option for sustained use.
Blemish Care Up Cream 55ml
The Blemish Care Up Cream 55ml provides the moisturising step in the Blemish Care Up routine. It is calibrated for oily and combination skin typical of blemish-prone routines, providing adequate hydration without adding weight or occluding congested pores. The cream works in tandem with the serum rather than replacing it - the serum addresses the active blemish concern, and the cream maintains the moisture balance that prevents skin from overproducing sebum in response to dehydration.
Apply the cream as the final routine step (before SPF in the morning, as the last layer in the evening). Use a small amount and avoid applying heavily over active blemishes, where a lighter touch is preferable to prevent further congestion.
Skincare Vegan Tone Up Sun 40ml: SPF with a Brightening Effect
The Skincare Vegan Tone Up Sun 40ml is the sun protection product in this collection. Tone-up sun products are a Korean SPF category that provides both UV protection and a subtle brightening or evening effect - they typically contain ingredients that scatter light to minimise the appearance of redness, uneven tone, and post-blemish marks. At 40ml it is a standard SPF size for daily facial use, lasting approximately two months with recommended amounts applied once daily.
The vegan designation means the formula uses no animal-derived ingredients, which is relevant for those who prefer vegan cosmetics. The tone-up effect is light rather than full coverage - it functions as an SPF primer rather than a base makeup product. Apply it as the final morning step after the serum and cream.
Where the Blemish Care Up Serum Fits in a Routine
The Blemish Care Up Serum applies at the serum step after toner and before cream. In a complete routine: cleanse - toner (from the broader ISOI Blemish Care range or another brand) - Blemish Care Up Serum (treatment step) - Blemish Care Up Cream 55ml (moisture) - Skincare Vegan Tone Up Sun 40ml (morning SPF). In the evening, skip the SPF and use the cream as the final layer.
The Up Serum can also be used alongside the standard ISOI Blemish Care Serum in the same routine by alternating them on different nights - using the Up Serum on evenings when more concentrated treatment is needed and the standard serum for maintenance nights - though most skin types will find one serum sufficient at the treatment step.
Using the Blemish Care Up Serum Daily
The Blemish Care Up Serum is designed for daily use morning and evening. Apply two to three drops or a half-pump to the face after toner, pressing gently into problem areas rather than spreading uniformly. For skin with localised congestion (nose, chin, or forehead rather than across the full face), focus the serum on those areas and use a lighter hand on non-congested zones. Consistent daily use over four to six weeks is needed to assess the serum's full effect on blemish frequency and post-blemish marks.
ISOI's Vegan Positioning in This Collection
The Skincare Vegan Tone Up Sun explicitly carries the vegan designation, indicating no animal-derived ingredients. ISOI's positioning as a brand includes botanical and natural ingredient sourcing more broadly, though not all ISOI products across the wider range carry an explicit vegan certification. If vegan formulation is a priority for your full routine, check the product page for each item to confirm the certification status of the specific product rather than assuming all ISOI products share the same vegan status.
FAQ
Frequently asked questions
FAQ
Frequently asked questions
Why does the ISOI Blemish Care Up Serum come in so many different sizes?
ISOI offers the Blemish Care Up Serum in seven sizes - from 15ml to 70ml - to match purchase commitment to different stages of use. A first-time buyer can trial the formula in a 15ml or 20ml without a large investment. A committed daily user who has confirmed the serum works for their skin can move to the 50ml or 70ml for better value per ml and fewer reorders. The formula is the same across all sizes, so the only decision is quantity.
Which Blemish Care Up Serum size should I buy for a first trial?
The 15ml or 20ml is the practical starting point for a first purchase. At 15ml you get approximately three to four weeks of daily use - enough time to see whether the formula reduces congestion and blemish frequency for your skin. If it works, the 50ml or 70ml is the better ongoing choice on a cost-per-ml basis. Avoid buying the 70ml first since committing to three months of a formula before confirming it works for your skin is unnecessary given the smaller sizes are available.
Is the Blemish Care Up Serum stronger than the standard ISOI Blemish Care Serum?
The Blemish Care Up Serum (the Up line) is positioned as an upgraded formula with a higher or more effective active concentration than the standard Blemish Care Serum. The Up designation reflects this difference in active load. If the standard Blemish Care Serum has not provided adequate improvement after consistent use, the Up Serum is the natural next step rather than switching to an unrelated formula. Start with the 25ml or 30ml of the Up Serum to test the upgrade before committing to a larger size.
Is the ISOI Blemish Care Up Cream 55ml a light or heavy moisturiser?
The Blemish Care Up Cream is calibrated for oily and combination skin, so it provides adequate moisture without a heavy feel. It is lighter than a rich dry-skin cream but more substantive than a gel moisturiser. Most combination skin types will find it appropriate for daily morning and evening use. Very dry skin types may want to layer an additional nourishing product on top of the Up Cream in the evening, or switch to a heavier cream from the Moisture Doctor line for dry patches.
Can I use the ISOI Skincare Vegan Tone Up Sun 40ml as my only morning SPF?
Yes, the Vegan Tone Up Sun 40ml provides SPF as a standalone daily sunscreen for morning use. Apply it as your final morning step after serum and cream, using approximately a half-teaspoon for adequate face coverage. The tone-up effect gives a slight brightening finish alongside the UV protection. At 40ml with daily use at the recommended amount, it lasts approximately two months. Reapply during the day if you spend extended time outdoors, using the stick format from another range if available, or applying a thin additional layer with a clean fingertip.
Does the Vegan Tone Up Sun 40ml provide full coverage over blemishes and post-inflammatory marks?
No. The Vegan Tone Up Sun is an SPF product with a light tone-up effect - it provides a subtle, light-scattering brightening finish but does not conceal active blemishes or dark marks. For coverage over post-blemish marks, a separate tinted moisturiser or foundation is needed on top of the SPF. The tone-up effect reduces the visibility of redness and uneven tone at a broad level rather than targeting specific spots.
Is the ISOI Blemish Care Up Serum suitable for oily acne-prone skin?
Yes. The Blemish Care Up Serum is designed specifically for oily, blemish-prone, and congested skin. Its active formula addresses congestion and blemish frequency without the skin-drying side effects of stronger pharmaceutical-grade blemish treatments. Oily skin types should apply the serum to the full face after toner and follow with the Blemish Care Up Cream to maintain moisture balance. Skipping the cream step increases the risk of the skin overproducing sebum to compensate for dehydration, which can worsen congestion.
What is a simple daily routine using just the Blemish Care Up products?
A minimal Blemish Care Up routine: cleanse (your existing cleanser) - apply Blemish Care Up Serum (any size, after toner if you use one) - Blemish Care Up Cream 55ml - Skincare Vegan Tone Up Sun 40ml in the morning. In the evening, skip the SPF and finish with the cream. This four-product morning routine and three-product evening routine covers treatment, moisture, and sun protection without requiring additional ISOI products. Add a toner from the broader ISOI range or another brand if you want a prep step before the serum.
Can sensitised skin use the Blemish Care Up Serum?
Sensitised skin should patch-test the Blemish Care Up Serum before full-face use, particularly because the Up formula contains a higher active concentration than the standard Blemish Care Serum. Apply a small amount to the inner wrist or behind the ear for 24 hours to check for irritation. If no reaction occurs, introduce the serum gradually - once daily in the evening rather than morning and evening - and build to twice daily over two weeks as the skin adapts. If irritation appears, revert to the standard Blemish Care Serum, which carries a lower active concentration.