Hi @Sensera
Welcome to the community.
First off, in general your site looks good, nice color choices and font also. A lot of content, text that explains things, and I like that you say “backed up with science” and do link studies.
But there are some general things and some technical. First, not sure that the main tagline is that good. “For 40+, we aim to move away from the sports/gym branding that is mostly targeted towards the younger generation.” It sounds like 40+ people do not go to the gym or just work out at home, and do not know the general benefits of creatine. Pass all marketing that it is focused on performance, and muscle growth. Some of your images and wording, “older adults,” feel like you target 70+. And Sensera Vs other brands part on the “Learn more” page is especially, how to say, not misleading but at least problematic. More of marketing and wording. You focus on one part/benefits of creatin, while others focus on the other benefits. For example, taret audience: Sensera-45+ generation, focused on healthy ageing, others-Athletes, bodybuilders & fitness enthusiasts. Do you think " fitness enthusiasts" over 45 are not focused on healthy aging? Do they just focus on the current moment? Or Focus: Vitality, clarity, longevity against Strength, size, endurance. Do you think building strength and endurance is just for show, or maybe good parts are doing it for vitality and longevity, health in general? And lastly: Quality: “Premium-grade, third-party tested” against “Quality varies widely”. Why is your product premium-grade? Because it has elegant pagaing? I could not find information on where your product is created and where it is third-party tested. On the other hand, on the market, there are a lot of products, and a lot of them are also marketed as premium, pure, Creapure… And a lot of good brands. So varies, is true but thnk most are on good, quality side. Bad one just disappears after a while.
Sorry for a lot of text
but your pitch is good, it can focus on good thing,s but it should not, left out, or just put people who work out as the opposite, almost negative. Like they are not also a target audience.
Now more technical things 
- On the homepage, the banner image looks low quality, and on wider screens, a lot of the top and bottom gets cut off. So it does not look good.
- On banner text, “Premium supplements” is plural, but I do see only one for now, at least.
- Your header is too big, when it is transparent, it is not so bad but when hovered or just white, for me, that is too much wasted space. Plus, on a white background, your logo is not so visible
- Reviews look fake, a bit convenient; they use all the keywords you need, plus on the actual product page, there are no reviews.
- 30-Day Money-Back Promise icon/text looks lonely, you could add a few more things like fast delivery, support, quality
- Then a few good sections, just last one needs a space, I think, to separate from the footer.
- Footer is good, but I would add contact information here. I could find them in Terms but they have a place on both the footer and contact page.
- On the product page, I find “30-Day Money-Back Promise” a bit odd, not aligned, and maybe not the best place. I would put it after the product info
- Did not get info on why it is premium? Where is it made? Do you have a lab that tests? What 3rd party lab tests it? Are the ingredients 100% true, and where is the nutritional information?
- Learn more page, besides the Vs section, Miths are a bit hard to read, maybe instead of the slider, just a grid would work fine.
- Contact us page, you ask phone number but you do not give yours.
- Again hero image is cut off on larger screens. Do check this out
And with this image, I also noticed, you are targeting 40+ men only, right? No image of women, no women in the community, do they take the same dosage 5g or 3g?
So in summary, solid site, but creatine has been popular for quite some time, a lot is said about it, and it is known. You are trying to rebrand it, focus on some other things but , for me, I did not see enough trust signals to buy your product from you.
Still, good luck and hope sales will come. It is a tough niche/market.