What’s actually
happening to
men over 35.
Testosterone. Vitamin D. Active B12. Inflammation. These aren’t wellness buzzwords. They are four of the key systems that directly explain why men over 35 stop feeling like themselves. Here are the facts.
The four systems
Testosterone, Vitamin D, Active B12 and inflammation. Each one has a section on this page: what it does, what the numbers mean, and what we do about yours.
1%
Per year
The rate at which testosterone declines in men from the age of 30. By 45, the average man has lost 10 to 15% of his peak testosterone. By 55, closer to 25%.
56%
Of UK men
UK men are estimated to be below optimal Vitamin D levels. Between October and April, even outdoor workers cannot produce sufficient Vitamin D from sunlight alone.
20%
Are deficient
An estimated 20% of UK adults have Active B12 levels below the threshold needed for normal cell function. The figure is higher in men over 40 and those who avoid meat or dairy. Standard B12 tests often miss it because they measure inactive fractions.
Testosterone
“Normal” is not
the same as good.
The NHS reference range for testosterone in men is roughly 8 to 30 nmol/L. That range was built to identify clinical hypogonadism: the level at which a man is medically deficient. A man at 8.5 nmol/L and a man at 24 nmol/L both get the same result from their GP: normal.
They are not the same. Not in how they feel. Not in their energy, recovery, or mental sharpness. The range exists to identify illness, not to optimise performance.
“GP said normal. That’s not the same as good.”
Research consistently shows that men with testosterone levels in the lower third of the “normal” range report significantly higher rates of fatigue, reduced libido, slower recovery, and mood changes than men in the upper third, despite both being technically “not ill.”
Also tested with testosterone
SHBG
Sex hormone-binding globulin. SHBG binds to testosterone and makes it inactive. A high SHBG can leave a man with technically “normal” total T but very low free T, the form that actually matters.
FAI
Your total testosterone as a percentage of your SHBG. It is on the panel and it is on your report, but in men we draw no conclusion from it: it tracks calculated free testosterone poorly, and it reads high exactly when SHBG is low. Read your Free T instead.
Albumin
The most abundant transport protein in your blood, and the second input to the free testosterone calculation after SHBG. Measuring it is what makes your Free T a calculated figure rather than an estimate.
Free T
Calculated from Total T, SHBG and Albumin. This is what your body can actually use. Two men can have identical total testosterone but very different free testosterone. Total T alone is an incomplete picture.
Testosterone: what the numbers mean
Below NHS threshold
NHS referral territory. Speak to your GP.
Borderline
Often dismissed by GPs. Symptoms are typically present. Below optimal, and worth a GP conversation.
In range. Not optimal.
Where most men with symptoms sit. Technically "normal." Functionally below par.
Healthy range
Most men with these levels feel well. Retest in 6 to 12 months.
Vitamin D
You can’t eat or train
your way out of this one.
Vitamin D is produced in the skin when it’s exposed to UVB radiation from sunlight. Between October and April in the UK, the angle of the sun is too low to trigger this reaction. For roughly six months of the year, no amount of time outdoors will produce meaningful Vitamin D.
Very few foods contain meaningful amounts of Vitamin D. The NHS advises everyone in the UK to consider supplementation from October to March. Most men don’t.
Vitamin D receptors are present in muscle tissue, the brain, and the immune system. Low Vitamin D directly affects energy, muscle function, and how quickly you recover from training.
EFSA-approved health claim
“Vitamin D contributes to normal muscle function.”
This is the legally verified claim we can make. Not more, not less.
What we recommend if yours is low
We will recommend supplements based on your result. Our own Daily Stack (launching shortly) will contain 4,000 IU of Vitamin D3, the dose most research suggests for moving levels from insufficient to optimal within 8 to 12 weeks. Diet alone is insufficient for most men in the UK. Join the early-access list at any time.
Vitamin D: what the numbers mean
Deficient
Associated with bone health issues, significant energy loss, muscle weakness. NHS will typically treat at this level.
Insufficient
Where most UK men sit in winter. Noticeable impact on energy and recovery. Common Andro Prime trigger.
Adequate
Functional. Most people feel reasonably well at this level.
Optimal
The range most research associates with peak muscle function, immune support, and energy. Target for supplementation.
Active B12
Your GP test
probably missed it.
B12 plays a central role in energy metabolism, neurological function, and red blood cell production. When it’s low, energy drops, mental sharpness suffers, and recovery slows. These are symptoms easy to attribute to stress, age, or overtraining.
The problem is that B12 deficiency is routinely underdiagnosed. GPs test total serum B12 when they test it at all. A result that comes back “normal” on that test can still indicate a functional deficiency when Active B12 is measured directly.
For men over 40, this is one of the more common findings. It is also one of the most straightforward to address, with the right form of supplementation.
Why standard B12 tests miss the problem
Most B12 blood tests measure total serum B12, which includes both the active and inactive fractions. You can have a technically “normal” total B12 result while your active B12 (the fraction your cells can actually use) is well below optimal.
Active B12 (Holotranscobalamin) is the specific marker that shows what’s available to your cells. It’s a more sensitive and clinically meaningful measure, and it’s what we test.
Deficiency becomes more common after 40. The stomach produces less intrinsic factor with age, which is required to absorb B12 from food. Plant-based diets significantly increase the risk regardless of age.
EFSA-approved health claims
“Vitamin B12 contributes to normal energy-yielding metabolism.”
“Vitamin B12 contributes to normal psychological function.”
These are the legally verified claims. Not marketing lines.
What we recommend if yours is low
We will recommend supplements based on your result. Our own Daily Stack (launching shortly) will contain 1,000mcg of Active B12 as Methylcobalamin. Methylcobalamin is the bioactive form: it is used directly by the body without requiring conversion. Most cheaper supplements use Cyanocobalamin, which your body must convert before it can use it. The form matters. Join the early-access list at any time.
hs-CRP and inflammation
Sore for three days.
Not just bad luck.
hs-CRP (high-sensitivity C-reactive protein) is a marker of systemic inflammation. When inflammation is elevated, the body’s ability to repair and recover is compromised. Training feels harder. Recovery takes longer. Joint stiffness becomes a fixture rather than an occasional irritation.
In active men, mildly elevated hs-CRP often reflects connective tissue stress. The body is dealing with more repair demand than it has the resources to handle, particularly when Vitamin D and Active B12 are also low, both of which support recovery processes.
Elevated inflammation is not something to push through. It’s information. It means something is causing the body to remain in a repair state.
Also tested: Ferritin
Ferritin is the body’s iron storage marker. Low ferritin means your muscles and tissues aren’t getting enough oxygen-carrying capacity, which directly affects stamina and recovery. If ferritin comes back low, we refer you to your GP. Iron supplementation needs to be dosed based on your specific levels. Getting it wrong can cause harm. We won’t sell you iron.
hs-CRP: what the numbers mean
Low risk
Normal. No action required for inflammation specifically.
Mildly elevated
Common in active men. Often reflects training stress. Collagen recommended if joint symptoms are present.
Elevated
Recovery deficit likely significant. Collagen recommended with joint symptoms. GP review if it stays elevated on retest.
High: see your GP
At this level, we don't recommend a supplement. We tell you to book a GP appointment. This warrants a conversation with a doctor.
The NHS gap
The system is
designed for illness.
Not performance.
The NHS testosterone threshold exists to identify men who are clinically hypogonadal, men who have a diagnosable deficiency that warrants treatment. It was designed for that purpose and it does that job well.
It was not designed to answer the question: “Am I functioning at a level that matches how I should feel at my age?” That is a different question. The NHS does not have the infrastructure, the appointment time, or the clinical mandate to answer it for most men.
This is not a criticism of GPs. It’s a structural reality. GPs have eight-minute appointments and clinical thresholds to work within. Optimisation is outside their scope in that context.
“Your GP isn’t wrong. They’re answering a different question. We answer yours.”
Why men don’t get tested
Our tests
Every marker we test.
Why it’s in there.
Nothing is included because it sounds impressive. Everything is included because it directly explains something specific about how you feel.
| Marker | What it measures | Why it matters | Included in |
|---|---|---|---|
| Total Testosterone | Total circulating testosterone in the blood | The primary male sex hormone. Affects energy, libido, muscle mass, mood, and drive. | Kit 1 & Kit 3 |
| SHBG | Sex hormone-binding globulin | Binds to testosterone and renders it inactive. High SHBG means less testosterone available to your cells regardless of total T. | Kit 1 & Kit 3 |
| Free Androgen Index | Your total testosterone expressed as a percentage of your SHBG | Reported for completeness, because it appears on lab reports you may be given elsewhere. In men we draw no conclusion from it: it tracks calculated free testosterone poorly. Your Free Testosterone result is the figure to work from. | Kit 1 & Kit 3 |
| Albumin | The most abundant transport protein in the blood | One of the two inputs, with SHBG, used to calculate your free testosterone from your total testosterone reading. Testing it is what makes that figure a calculation rather than an estimate. | Kit 1 & Kit 3 |
| Free Testosterone | Calculated from Total T, SHBG and Albumin | The biologically active fraction. This is what your body actually uses. Total T on its own does not tell you how much of it is available to you. | Kit 1 & Kit 3 |
| Vitamin D | 25-hydroxyvitamin D (total) | Supports muscle function, immune response, and energy. Most UK men are below optimal between October and April. | Kit 2 & Kit 3 |
| Active B12 | Holotranscobalamin (active form) | The form of B12 your cells can actually use. Standard B12 tests measure total serum B12 which includes inactive fractions. Active B12 shows what is truly available. Deficiency is more common in men over 40 and those on plant-based diets. | Kit 2 & Kit 3 |
| hs-CRP | High-sensitivity C-reactive protein | Systemic inflammation marker. Elevated hs-CRP is directly associated with slower recovery, joint soreness, and reduced training adaptation. | Kit 2 & Kit 3 |
| Ferritin | Iron storage marker | Low ferritin limits oxygen delivery to muscles and tissues. Causes fatigue and stamina decline that is often mistaken for overtraining or low testosterone. | Kit 2 & Kit 3 |
Scroll to see all columns →
These markers were chosen because they are the most clinically relevant indicators of the specific symptoms this cohort presents with: fatigue, slow recovery, low drive. We don’t test 30 markers to make the panel look impressive. We test the nine that actually answer the question.
On supplements
We don’t trust
supplements either.
Unless there’s a reason.
We will not recommend a supplement unless your blood result shows a specific deficiency that it directly addresses. If your Vitamin D is fine, you will not see a Daily Stack recommendation. If your inflammation is mildly elevated but you don’t have joint symptoms, you won’t see a Collagen recommendation.
Every ingredient in our supplements has an EFSA-approved health claim. That means the European Food Safety Authority has reviewed the evidence and confirmed the claim is substantiated. We use the exact approved language, nothing more.
Our supplements do not diagnose, treat, or cure. They support normal physiological function where a deficiency has been confirmed. That is an important distinction and we will always be straight about it.
We do not recommend supplements when there is nothing to address. If your results come back fully in range, your dashboard will say so. No product, no upsell. Come back in 6 to 12 months for a retest.
Daily Stack
Zinc, Active B12 (Methylcobalamin), Vitamin D3. Launching shortly. Join the early-access list at any time.
EFSA-approved claims
Zinc: “Contributes to the maintenance of normal testosterone levels.”
Active B12: “Contributes to normal energy-yielding metabolism.”
Vitamin D3: “Contributes to normal muscle function.”
Joint & Recovery Collagen
Hydrolysed collagen peptides plus Vitamin C. Launching shortly. Only recommended when hs-CRP is elevated AND joint symptoms are present.
EFSA-approved claim
Vitamin C: “Contributes to normal collagen formation for the normal function of cartilage.”
Why this price
Why do your tests cost more
than a £45 test?
Our panels cost more than a basic entry test. That buys the markers that matter for men, including free testosterone via FAI, analysis by a UKAS ISO 15189-accredited lab, plain-English results under recommendation logic approved by a GMC-registered GP, and a business with no stake in your result coming back low.
Ready to find out
Find out what your blood is telling you.
£99 to £179. Five minutes. Results in 2 to 5 working days. A UKAS ISO 15189-accredited lab. Plain English. A specific recommendation based on your actual numbers.
No GP required. Discreet packaging. Supplement range launches shortly.