I’ve had Medik8 in my routine for two years now. Long enough to genuinely know what works, what I keep repurchasing, and what I’m ready to level up from. So are Medik8 C-Tetra and Crystal Retinal really worth it? Here’s my 2-year review
Affiliate disclosure: This post contains affiliate links. By clicking, you get 20% off, and I earn a small commission if you buy through them, at no extra cost to you. All products mentioned were bought with my own money. This isn’t a paid partnership. It’s a genuine roundup of products I’ve used, love, and am ready to upgrade from.
Here’s your 20% off link
Okay, on with what I really think of my Medik8 products 2 years in…
If you follow me on TikTok you’ll know I don’t do blanket brand recommendations. I read INCI lists, I question marketing claims, and I only stay loyal to products that keep earning their place. Medik8 has stayed the course, which is rare in over 40s skincare, so it feels like the right moment to write about what I’ve genuinely loved.
I only stay loyal to products that keep earning their place. Medik8 has stayed the course, which is rare in over 40s skincare.
-Claire
C-Tetra (and my recent upgrade to C-Tetra Luxe)
C-Tetra was my gateway into Medik8 and to the THDA form of vitamin C. If you’ve watched my vitamin C content you’ll know THDA (Tetrahexyldecyl Ascorbate) is the gentler, oil-soluble form that sits beautifully on over 40s skin without the sting of pure L-ascorbic acid.
I used the standard C-Tetra for over a year. Genuinely no complaints. It layered well, absorbed cleanly, and my skin never rebelled. It became one of those quiet workhorses in my routine that I stopped thinking about because it just did its job.
However, a few months ago I moved up to C-Tetra Luxe, which uses the same THDA form at a higher concentration alongside a fuller antioxidant complex. The texture is slightly richer, the absorption is slower in the best possible way, and I’ve noticed my morning skin looking more even over time.
Am I thinking about moving to Super C 30+ next? Honestly, yes. The 30% THDA formulation is the strongest gentle-form vitamin C on the mass market, and after two years of building tolerance, I’m ready for the next level. That’s the thing with proper vitamin C. It’s a slow-build ingredient. You don’t jump in at 30%. You earn your way there.
Crystal Retinal (I’ve done 1, then 3, and I’m going to 6 next)
Crystal Retinal is my retinoid of choice on my non-tret nights. Retinaldehyde is one conversion step away from retinoic acid, which means it works faster than retinol without needing prescription-level strength. It’s the sweet spot for over 40s skin that wants results without the barrier stress.
I started on Crystal Retinal 1 because that’s what you do. You start low, you take it slowly, you let your skin build tolerance. After several months, I moved up to 3. Now I’m ready for 6.
The reason I love Medik8’s retinaldehyde specifically is the delivery system. It’s time-release, which means less irritation and a more even response over the night. My skin isn’t red the next morning. My barrier stays comfortable. And the results build genuinely over 12 weeks, not three days.
If you’re brand new to retinoids, please don’t start at 6. Start at 1 and give yourself the time. Retinoids reward patience.
The Honest Verdict – Are Medik8 C-Tetra and Crystal Retinal Worth It?
Medik8 has stayed in my routine because the science is real, the formulations are honest, and the results are gradual in the way over 40s skin genuinely needs. It’s not the cheapest brand out there, but the products earn their price in a way I’ve come to trust.
So are Medik8 C-Tetra and Crystal Retinal worth it? I definitely think so; I can actually see the difference in my skin when I use them.
If you want to give any of them a try, my affiliate link below gives you 20% off. I only share this because I use these products myself.
Here’s your 20% off link
Affiliate disclosure reminder: I earn a small commission if you buy through my link, at no extra cost to you. This isn’t a paid partnership. Everything above was bought with my own money.
Tell me in the comments if you’ve tried any of these, or if you’re considering starting. I love comparing notes.
