tldr; it was the right side- but you can’t tell. There is no noticeable difference.

Methodology

There was no noticeable difference in skin quality between the two sides of my face.

I applied the serum once in the morning when I woke up and once at night before bed. I started on Nov 15, 2025 and ended on April 18th, 2026. I was diligent and probably missed fewer than 10 applications over that period. I used approximately 1/2 a dropper for each application, which was more than enough to thoroughly cover the right half of my face.

I did not use the moisturizer or the cleanser since I was specifically interesting in seeing the impact of the main active ingredients in the serum (SFC and NMN).

Results

I had planned to make a fancy randomized survey to cancel out any left/right, lighting, and daily variation biases leaving only the treatment/non-treatment differences. This turned out to be wholly unnecessary because nobody I’ve asked in the past few weeks was able to see any difference at all between the two sides. Of the few people willing to guess, the answers were evenly split.

Here are some high-res photos from the day after the test, but honestly if you think you see a difference then it is probably just lighting. If anything, the control side looked slightly better IRL (but that changes from day to day).

Treatment

Control

The Take-away

Topical treatments that claim to improve the appearance of your skin are so easy to empirically test. If you are considering using one then you have no excuse not to try it on only one side of your face first to find out if it really works before you fully commit your time and money.

You should also try to do more testing generally, especially when it is easy and the answers would be conclusive.

And the younger you are, the more effort you should devote to testing since you will have more time to avoid the costs/collect the gains.

Disclaimer

My results here only apply to me – my age, my environment, my skin. If this skin serum works for you then that’s great, I’d just urge you to actually test it before deciding that it works – and a one-side test is better than a before/after test because so many other things can confound a before/after.

FAQ

Q: Why 6 months?
A: The product listing says…

After 12 weeks I didn’t notice any difference, but I wanted to be 100% sure so I kept going.

Q: Why didn’t you do [some fancy scientific latent skin property measurement]?
A: Luckily most of the claims for this product are specifically about _visible_ effects…

• “Helps skin look refreshed”
• “Calms visible irritation”
• “Combats texture and redness”
• “Supports visibly firmer looking skin”
• “SFC and NMN target visible signs of aging”

…so if can’t see it (and no one else can either), then as far as I am concerned it does not do what it claims to do.

Q: If it did work then you would have looked like a freak.
A: If it had worked, I would have then switched sides until the two sides looked the same and then happily started using it on both sides. Small price compared to either (1) never using it and it does work, or (2) using it for the rest of my life not knowing that it doesn’t work.

Q: Why do you hate Bryan Johnson?
A: I don’t. I think he nails the big and important advice (sleep, eat, and exercise) and I understand the other hyperbolic stuff as a way to get attention to deliver the big and important advice.

That said, I do think some of the products in the Blueprint product line dilute Bryan Johnson’s personal brand. If it was me, I’d limit the coverage to only products that are absolutely bright-line effective and are not easily available from any other source. Then I’d make sure to really and truly nail the quality every time. The most valuable thing he has to offer is his credibility, so don’t squander that.

Q: What else should I be testing?
A: I have many friends who lament how much they miss pasta and bread because they became convinced that they are gluten intolerant. Yet they have never done a conclusive test to check… and it is so easy. The couple of people I have convinced to actually try the test have been shocked and elated to find out that gluten had zero measurable effect on them.

Q: What’s your gluten test?
A: You basically just have to eat gluten in a way where you don’t know that you are eating gluten except for the presumed effects. So, for example, you can make up 20 sets of pills with 10 sets of gluten and 10 sets of something that looks like gluten but that you are confident that you will not have a reaction to (maybe rice flour?). Make sure you use enough gluten that you are sure you would feel it. Put the sets into containers and mark which are which and mix them up. (Ideally have someone else do the previous steps for you). Now each day for the next 20 days take one set of pills (avoid seeing the marking) and keep track of how you feel for for each day and if you think it was a gluten day and how confident you are. At the end of the 20 days compare your notes to the actual order of the sets.

If you do try this test and you turn out to be significantly and objectively gluten sensitive (and do not have celiac’s), then please comment because I would very much like to know this!

Q: What’s next?
A: I’ll probably do a half-face of hardcore prescription strength retinoids, but I am open to suggestions. I would also do a half-head of the Blueprint laser hat if someone wanted to send me one. :)

NOTE: Two FAQs elided 4/22/2026 for unnecessary snarkyness.