My Blood Results Changed How I Supplement. Here's What They Found.

My ferritin was low. I'd been taking iron for eighteen months.

My vitamin D was suboptimal. I'd been supplementing it every single morning.

I didn't know either of those things until I did a blood test. I'm not sure I ever would have found out without one.

I'd been meaning to get tested for a long time. It kept getting pushed — life, cost, the vague sense that I was probably fine. What finally made me do it was realising that my monthly supplement restock had crept to a point where I genuinely couldn't tell you what, if anything, was actually doing something. Iron, vitamin D, B12, magnesium — all started off the back of some article or recommendation and just kept going, on autopilot.

So I bought an at-home blood test with Healf Bloods.

I'd assumed it would involve squeezing blood from my finger like I'd done before. It wasn't that at all. The Tasso device goes on your upper arm, you barely feel it, the whole thing took about fifteen minutes. I posted it back the same day.

Results came back within 72 hours — a plain-English dashboard, not a printout full of ranges I'd have to decode on Google. My ferritin was flagged. Not catastrophically low, but enough to explain a lot — the 3pm wall, the months of feeling like I was operating at about 80%. My oestradiol also needed attention, which I hadn't even thought to look at.

I had a 1:1 with one of their nutritionists the following week. She said something that stuck: most people supplement based on what they've read generally, not what their body actually needs right now. She adjusted my protocol — different form of iron, higher vitamin D dose, a few things I hadn't been thinking about at all.

Six months later. Ferritin up. Energy noticeably, consistently different. First time in about a year I stopped hitting that 3pm wall.

The thing I keep thinking about: I spent eighteen months buying supplements to fix something I'd never actually measured. The Healf Bloods test cost less than those eighteen months of guessing.

What Healf Bloods includes:

• 35+ biomarkers — hormones, iron markers, vitamin D, inflammation, thyroid and more
• No clinic, no GP referral — the Tasso device collects from your upper arm at home
• Results in 72 hours via a plain-English dashboard (not a lab printout full of ranges you have to decode)
• 1:1 nutritionist consultation included in the price
• Personalised recommendations based on your specific results