Cell turnover
Accelerates the exfoliation of old keratinocytes, the cells that dull the surface when they stay on too long.
Nightly renewal without irritation. A retinol engine unlike most others, stabilized by Vitamin E.
"Maximized Skincare. Transderma A and C."Teresa Grundin · Elle.se, 2014
Serum A is a precision-engineered retinol formulation that works deeply in the basal layers of the skin to accelerate exfoliation and stimulate the formation of collagen and elastin. As dead cells shed, fine lines, surface texture, and scars visibly soften. The skin renews itself; the serum provides the trigger.
The active form is retinyl palmitate, which converts to retinol once inside the skin: a gentler, more controlled delivery than direct retinol in an irritating base. It is stabilized by Vitamin E (Alpha-Tocopherol Acetate), which protects the active from oxidation and keeps the formula stable bottle to drop.
"The body functions during the day and recovers, regenerates, and heals during the night. Serum A is built around that rhythm."
Serum A is a night formula. Pair it with Serum C by day; the two work on the same structural proteins from opposite directions.
The formula is built on squalane (a lipid that skin recognizes) as a delivery base, with an isosorbide co-solvent, Vitamin E as a stabilizer, and retinyl palmitate as the active. Anhydrous, with no preservatives, fragrance, or fillers. Every molecule has a role, and the bottle stays potent for two years from the first drop to the last.
A skin-identical lipid that carries the actives through the barrier without disrupting it. Non-comedogenic, anti-inflammatory, and a natural part of human sebum.
A gentle solvent derived from sugar. Dissolves the retinyl palmitate into the lipid base and enhances its penetration without added water.
Prevents the oxidation of retinyl palmitate. Also functions as an antioxidant in its own right, supporting the skin's own defense against free-radical damage.
A gentler ester of Vitamin A that converts to retinol once inside the skin. Drives cell turnover, softens wrinkles, and supports collagen synthesis. The single most-studied topical anti-aging active.
Apply Serum A nightly to clean, dry skin. Unlike most retinols, Serum A is non-irritating: a gentler converted form, stabilized by Vitamin E. Use every night from the start, with no need to build up.
Cleanse and dry face and neck before bed. One to two drops across bare skin; avoid the immediate eye area.
One to five minutes for the serum to sink in fully.
Finish with Transderma Moisture Serum (M) if your skin needs it. Let it absorb completely.
Once completely absorbed, you can continue with your usual routine: sunscreen, makeup, anything you normally use.
Every night, from day one. Unlike most retinols, Serum A doesn't require a slow build-up. The gentler converted form and Vitamin E partner make nightly use comfortable from the first application.
Retinol is one of the most extensively studied topical actives in dermatology. Serum A delivers it with a gentler converted form and a stabilizing partner, so the benefits accumulate without the irritation typical of harsher retinol products.
Accelerates the exfoliation of old keratinocytes, the cells that dull the surface when they stay on too long.
Stimulates collagen and elastin production, reducing the depth and visibility of fine lines and expression wrinkles.
Evens out rough patches, pigmentation, and post-acne marks as the skin cycles through faster.
Maintains the structural quality of the skin over time: the kind of change that shows up after weeks, not hours.
Serum A is complete as a night routine. Paired with C, M, or O, it becomes the night half of a full day/night system built around cellular turnover and regeneration.

The day counterpart. Vitamin C stimulates collagen; A drives turnover. C by day, A by night: a complete anti-aging pair.

Layer after Serum A absorbs to soothe any transitional dryness from increased turnover. Ceramides rebuild the barrier.

Feeds the mitochondria that power turnover and collagen synthesis. Amplifies what A starts at night.
Free standard shipping on orders over $150. Delivered worldwide from Stockholm. Full shipping details.
14 days from invoice date. Products in original packaging, refunded to the original payment method. Returns policy.
Laboratory approved by Läkemedelsverket. Registered under EU Cosmetics Legislation. Never tested on animals.