Questions,
answered.

No water, no fillers, no preservatives. Every drop is active formula, stabilized by squalane, a skin-identical lipid that carries the vitamins past the stratum corneum into the dermis, where collagen synthesis and cellular renewal actually happen. Most serums are 65–85% water and stop at the surface. Transderma doesn't.

Yes. All five formulas are vegan, and Transderma has never tested on animals. The serums are registered under EU Cosmetics Legislation and laboratory-approved by Läkemedelsverket (the Swedish Medical Products Agency).

No. Because there's no water in the formula, there's no bacterial growth to prevent, so no preservatives are needed. No added fragrance, no colorant, no emulsifiers. Only functional ingredients that are in the bottle for a reason.

2 years unopened. At least 12 months after first use. The airless pump packaging protects the formula from oxygen and contamination throughout the bottle's life, including the final drops, which are as potent as the first.

Serum A contains retinyl palmitate (Vitamin A) and is not recommended during pregnancy or breastfeeding. Serums C, O, M, and R are generally considered safe, but we recommend confirming with your healthcare provider before starting any new skincare during this period.

Yes. The absence of water, preservatives, fragrance, and alcohol makes these formulas appropriate for reactive, sensitive, and compromised skin. Serum M is specifically designed for dry, sensitive, and mature skin. It can be used on its own or as a barrier repair step. If you're new to active skincare, start with one serum at a time for a week or two to monitor how your skin responds.

Apply on clean, dry skin. In the morning: Serum C or O first, then (optional) Serum M as the closing layer. At night: Serum A on bare skin, then Serum M. Serum R can be layered day or night, after the active and before M.

Rule of thumb: active vitamin first, Serum M last.

Two drops is usually enough for face and neck. These formulas are concentrated. More product doesn't mean better absorption. Excess just sits on the skin surface.

Yes, though the more products you layer, the harder it becomes to isolate what's actually working. If you combine Transderma with products from other brands, apply Transderma first to clean, bare skin, let it absorb, then layer other products on top. Avoid combining with other retinoids if you're already using Serum A.

Start with 2–3 nights per week for the first two weeks. Build up to nightly use as your skin tolerates it. Always pair with SPF during the day; retinoids can increase photosensitivity. If you experience dryness or flaking, reduce frequency and layer Serum M on top.

Yes — and especially with Serum A. Retinol increases the skin's photosensitivity, so a daily broad-spectrum SPF is non-negotiable any day you've used it the night before. Skipping sunscreen with retinol undoes most of the work.

For the daytime serums, the case is different but the answer is the same. Vitamin C pairs naturally with SPF — it works as an antioxidant defense against UV-induced free radicals, so the two are complementary. Apply your serum first, give it a minute or two to absorb, then layer your sunscreen on top.

As a general rule, treat daily SPF as the foundation of any active routine. The serums do the deep work; sunscreen protects what they've built.

Often, no. Serum M is formulated to replace a standard moisturizer entirely, rebuilding the barrier with skin-identical lipids and ceramides rather than sealing the surface with occlusive petrolatum or coating it in silicones. If you normally reach for a cream after your active serum, try Serum M as the final step for a few weeks and see if you still miss the cream.

Most people notice visible changes (brighter tone, smoother texture, a calmer barrier) within 2–4 weeks of consistent use. Deeper changes like fading pigmentation, fine line softening, and barrier rebuilding develop over 8–12 weeks. Skin turnover is a slow biological process; patience pays.

Serum R is formulated specifically for post-inflammatory pigmentation and uneven tone. Trans-resveratrol and piceid target the pigment that lingers after the blemish is long gone. Serum A accelerates cell turnover, which helps fade scars and smooth texture. Both work best consistently, layered appropriately, over 8–12 weeks.

Serum M (barrier) and Serum R (resveratrol) are generally suitable for acne-prone skin. Serum A can help with non-inflammatory acne (blackheads, whiteheads, congestion), but introduce it slowly. For severe, persistent, or cystic acne, we recommend consulting a dermatologist before adding Transderma.

Serum A drives cell turnover and supports collagen production; Serum C strengthens the dermal structure underneath. Used together (A at night, C in the morning), they address fine lines from two complementary angles.

Absolutely. Many long-term customers use only two or three of the five. The Discovery Kit lets you try all five at pocket size for $70 before committing, and our Skin Concerns page pairs specific concerns with the serums built for them.

All orders ship from Stockholm.

• Europe: 3–7 business days
• North America: 7–14 business days
• Rest of world: 10–21 business days

Express shipping is available at checkout. Full shipping details.

Yes, we ship worldwide. Orders over $150 ship free. International customs fees and import taxes are the responsibility of the recipient and vary by country.

Yes. A tracking number is emailed to you as soon as the parcel leaves Stockholm.

We accept returns within 14 days of invoice date. Products must be in original packaging. Refunds are processed to the original payment method. The Discovery Kit, once opened, is non-refundable. Full returns policy.

Email information@transdermaserums.com within 7 days of delivery with a photograph of the damage. We'll replace the affected product at no additional cost.

Yes. Digital gift certificates are available in any denomination. Purchase a gift certificate.

If you need to change or cancel, email us at information@transdermaserums.com within 2 hours of placing the order. Once the order has entered fulfillment we may not be able to make changes, but we'll always try.

Enter the code in the Discount field at checkout. One promo code per order.

All major credit and debit cards (Visa, Mastercard, Amex), Apple Pay, Google Pay, Klarna, and PayPal. Payment is processed by Shopify with full SSL encryption.

Not currently. Because the airless pump delivers exactly the dose your skin needs and the formulas last 2–3 months of daily use, most customers reorder once a quarter. If you'd like us to remind you when to reorder, drop us a note.