Medik8

The Crystal Retinal range and the CSA philosophy: Vitamin C in the morning, SPF every day, and Vitamin A (retinol or retinal) at night. It sounds simple because it is, and that's the point. Medik8 built its reputation by cutting through the noise of complicated routines and landing on three things that actually move the needle for most skin types.

Their retinaldehyde-based serums are particularly well-regarded. Retinaldehyde sits between retinol and prescription tretinoin in potency, which means faster results than standard retinol with less of the irritation and peeling that puts a lot of people off using retinoids altogether. Medik8 skincare is a favourite among dermatologists for that reason.

Yes, and it's one of the brand's strengths. Crystal Retinal 3 is specifically formulated as a gentle entry point, and their cleansers and moisturisers are fragrance-free and developed with the skin barrier in mind. If you've had reactions to other active skincare brands, starting with the Medik8 cleanser NZ and a hydrating moisturiser before introducing actives is the sensible approach. Let your skin adjust before going in with the stronger stuff.

What's the difference between Medik8 Crystal Retinal 3 and 6?
The number is the concentration of retinaldehyde. Higher number, stronger formula. Here's how to think about it:

Crystal Retinal 3 (0.03% retinaldehyde): the starting point. Gentler, suited to retinol beginners, reactive skin, or anyone who's had irritation with retinoids before
Crystal Retinal 6 (0.06% retinaldehyde): the next step up, once your skin has built tolerance over 8 to 12 weeks
Crystal Retinal 10 and above: for experienced retinoid users who have built up tolerance over time

Medik8 retinol NZ is available in both strengths at Synergy Hair. The general advice is to start at 3, be consistent for a couple of months, then reassess.

Morning, always. Medik8 vitamin C is an antioxidant designed to protect the skin from free radical damage caused by UV exposure and pollution during the day. Apply after cleansing and before SPF. Using it at night wastes the UV protection benefit, and some vitamin C formulas increase photosensitivity if there's residue on the skin when you go outside the next morning. Medik8 C Tetra is the go-to morning vitamin C in the range.

Medik8 peptides, including the Liquid Peptides serum, send signals to the skin to produce more collagen and elastin. Peptides are short chains of amino acids that act as messengers, prompting the skin's own repair processes to kick in rather than doing the work themselves. The result builds over time rather than being immediate, which is worth knowing before you expect overnight results.

Unlike retinoids, peptides cause no irritation and can be used morning or evening. That makes Medik8 liquid peptides an excellent option for people building toward a stronger active routine, or as a gentler complement to retinol for those who find retinoids alone a bit much.

Yes. Synergy Hair is an authorised Medik8 NZ stockist with the full range online. Free express shipping on orders $80+, overnight delivery to most NZ addresses, and a complimentary sample with every order. In-store advice is available at selected Synergy Hair salons for anyone wanting a skin consultation before buying.

Yes, but not at the same time and not on the same application. Medik8's CSA routine separates them deliberately: vitamin C in the morning, retinal or Medik8 retinol NZ at night. Applying them together can reduce the effectiveness of both and increase the chance of irritation. AM vitamin C, PM retinol. That's the structure the whole Medik8 skincare system is built around, and it works because the ingredients are doing different jobs at different times.