Men’s Ultimate Blood Test Kit

Testosterone is the primary male sex hormone, produced mainly by the Leydig cells in the testes (with a small amount from the adrenal glands). It's responsible for the development of male physical characteristics during puberty and maintains male traits throughout life. Beyond sexual function, testosterone affects muscle mass and strength, bone density, fat distribution, red blood cell production, mood, energy levels, and cognitive function. Testosterone levels naturally decline with age—typically by about 1-2% per year after age 30. However, the rate of decline varies considerably between individuals, and many men maintain healthy testosterone levels well into old age. Low testosterone (hypogonadism) can cause symptoms including reduced libido, erectile dysfunction, fatigue, low mood, difficulty concentrating, loss of muscle mass, increased body fat, reduced body hair, and decreased bone density. However, these symptoms are non-specific and can have many other causes. Normal total testosterone for adult men is typically 8.6-29 nmol/L, though ranges vary between laboratories. Because testosterone has a marked diurnal rhythm (highest in the morning, lowest in the evening), samples should be collected between 7am and 10am for accurate assessment. Low testosterone should be confirmed with a repeat morning sample before any diagnosis is made. If testosterone is low, further investigation (including LH, FSH, SHBG, and prolactin) is needed to determine the cause. Results outside the normal range may need a follow-up with your GP.

Ferritin is a protein that stores iron inside cells, primarily in the liver, spleen, and bone marrow. A small amount of ferritin circulates in the blood, and measuring serum ferritin provides the best estimate of total body iron stores. Unlike serum iron (which fluctuates throughout the day and with meals), ferritin is relatively stable and gives a more reliable picture of iron status. While iron deficiency is more common in women (due to menstrual blood loss), men can also become iron deficient—particularly with gastrointestinal blood loss (ulcers, colon polyps, colon cancer), vegetarian/vegan diets, intense endurance exercise, or regular blood donation. Low ferritin causes fatigue, weakness, shortness of breath, reduced exercise tolerance, and cognitive difficulties. Conversely, iron overload (haemochromatosis) is more common in men and can cause serious organ damage if untreated. Normal ferritin for men is typically 30-400 µg/L. Levels below 30 µg/L indicate depleted iron stores and likely iron deficiency. Very low levels (below 15 µg/L) indicate significant depletion. However, ferritin is also an acute phase reactant—it rises with inflammation, infection, and liver disease, potentially masking underlying iron deficiency. High ferritin (above 300-400 µg/L) in the absence of inflammation should prompt investigation for iron overload, particularly in men with Northern European ancestry. Results outside the normal range may need a follow-up with your GP.

Bilirubin is a yellow-orange pigment produced when the liver breaks down old red blood cells. The haemoglobin from these cells is converted to bilirubin, which is then processed by the liver, excreted into bile, and eliminated through the intestines (giving stool its brown colour). A small amount of bilirubin circulates in the blood at any time. Elevated bilirubin can occur when the liver cannot process bilirubin efficiently (liver disease, hepatitis), when bile flow is blocked (gallstones, bile duct obstruction), or when red blood cells are breaking down too quickly (haemolysis). Visible jaundice (yellowing of skin and eyes) typically occurs when bilirubin exceeds 2-3 times the upper limit of normal. Mildly elevated bilirubin is common and often due to Gilbert's syndrome—a benign genetic condition affecting about 5-10% of the population. Normal bilirubin is typically below 21 µmol/L. Mild elevations (21-40 µmol/L) are often due to Gilbert's syndrome, which is harmless. Higher elevations warrant investigation for liver disease, biliary obstruction, or haemolysis. Bilirubin should be interpreted alongside other liver markers (ALT, ALP, GGT) to understand the pattern and likely cause. Results outside the normal range may need a follow-up with your GP.

Alkaline phosphatase (ALP) is an enzyme found in several tissues, primarily the liver, bones, kidneys, and intestines. In the liver, ALP is concentrated in the cells lining the bile ducts. Elevated ALP typically indicates either liver/biliary disease or bone disease, and other tests (particularly GGT) help distinguish between these sources. Liver-related ALP elevations occur with bile duct obstruction (gallstones, tumours), cholestatic liver disease, or infiltrative liver conditions. Bone-related ALP elevations occur with increased bone turnover—Paget's disease, bone metastases, healing fractures, or rapid bone growth. Normal bone growth in adolescents causes physiologically elevated ALP. If ALP is elevated, checking GGT helps determine the source: elevated GGT alongside ALP suggests a liver/biliary cause; normal GGT with elevated ALP suggests a bone source. Normal ALP for adults is typically 30-130 U/L, though ranges vary between laboratories and assays. Mild isolated ALP elevation is often benign, but significant elevations warrant investigation. ALP should be interpreted alongside other liver markers and in clinical context. Results outside the normal range may need a follow-up with your GP.

Alanine aminotransferase (ALT) is an enzyme found predominantly in the liver, with smaller amounts in the kidneys, heart, and muscles. When liver cells are damaged or inflamed, they release ALT into the bloodstream, making it a sensitive marker of liver injury. ALT is more specific to the liver than AST (another liver enzyme), so ALT is often considered the primary marker of liver cell damage. Common causes of elevated ALT include non-alcoholic fatty liver disease (NAFLD)—increasingly common and strongly associated with obesity, metabolic syndrome, and type 2 diabetes—alcohol-related liver disease, viral hepatitis (B and C), medications (including some painkillers, statins, and antibiotics), and autoimmune liver disease. Intense exercise can also temporarily elevate ALT. Fatty liver disease is now the most common cause of elevated ALT in developed countries. Normal ALT for men is typically below 40-50 U/L, though some laboratories use lower thresholds. Even "high-normal" ALT (30-40 U/L) may indicate fatty liver in some individuals. Elevated ALT should prompt consideration of lifestyle factors (weight, alcohol, diet), medication review, and possibly further investigation including liver ultrasound and hepatitis serology. Persistently elevated ALT (>2x upper limit) warrants medical evaluation. Results outside the normal range may need a follow-up with your GP.

Gamma-glutamyl transferase (GGT) is an enzyme found mainly in the liver, particularly in cells lining the bile ducts. GGT is one of the most sensitive indicators of liver and bile duct problems, though it's not very specific—many factors can elevate GGT. It's particularly useful for distinguishing liver from bone disease (GGT is elevated in liver disease but not bone disease) and for detecting alcohol-related liver damage. GGT is notably sensitive to alcohol consumption and is elevated in approximately 75% of heavy drinkers. Even moderate alcohol intake can raise GGT, and it's often used as a marker of alcohol consumption. Other causes of elevated GGT include fatty liver disease, cholestatic liver conditions, medications (including anticonvulsants and certain antibiotics), diabetes, obesity, and heart failure. GGT tends to rise with age and is generally higher in men than women. Normal GGT for men is typically below 50-60 U/L. Elevated GGT, particularly in combination with elevated ALT, suggests liver pathology warranting further investigation. Isolated GGT elevation with normal ALT is common and may reflect alcohol use, enzyme induction by medications, or fatty liver. If you've had elevated GGT previously and have reduced alcohol intake, repeat testing can show improvement. Results outside the normal range may need a follow-up with your GP.

Creatinine is a waste product generated from the normal breakdown of creatine phosphate in muscle tissue. It's produced at a fairly constant rate (depending on muscle mass) and is filtered out of the blood exclusively by the kidneys. Because the kidneys are responsible for clearing creatinine, elevated blood levels indicate reduced kidney function. Creatinine is one of the most useful markers for assessing kidney health. Creatinine levels are influenced by muscle mass—men typically have higher creatinine than women, and muscular individuals have higher levels than those with less muscle. This is normal and doesn't indicate kidney problems. Very intense exercise can also temporarily elevate creatinine. This is why creatinine is used to calculate eGFR (which adjusts for age and sex) rather than being interpreted alone. Normal creatinine for men is typically 60-110 µmol/L, though ranges vary with muscle mass. Elevated creatinine may indicate reduced kidney function but should be confirmed with repeat testing and interpreted alongside eGFR. Temporary elevations can occur with dehydration, intense exercise, high protein intake, or certain medications. Persistently elevated creatinine warrants further investigation of kidney function. Results outside the normal range may need a follow-up with your GP.

The estimated Glomerular Filtration Rate (eGFR) is calculated from your creatinine level, age, and sex to estimate how much blood your kidneys filter per minute. The glomeruli are tiny filtering units within the kidneys where blood is filtered and waste products are removed. eGFR is considered the best overall measure of kidney function and is used to stage chronic kidney disease (CKD). eGFR declines naturally with age—kidney function typically decreases by about 1 mL/min per year after age 30-40. An eGFR of 70-80 in a healthy 70-year-old may be entirely normal, while the same reading in a 30-year-old would warrant investigation. The eGFR calculation accounts for age and sex but cannot account for muscle mass variations, which is a limitation. Normal eGFR is above 90 mL/min/1.73m². Mildly reduced function (60-89) may be normal for older adults. Sustained eGFR below 60 for more than 3 months defines chronic kidney disease: Stage 3a (45-59), Stage 3b (30-44), Stage 4 (15-29), and Stage 5 (<15, may need dialysis). A single eGFR result should not be over-interpreted—kidney function can fluctuate, and CKD requires persistent abnormalities. Results outside the normal range may need a follow-up with your GP.

Cholesterol is a waxy, fat-like substance that's essential for life—it's a building block for cell membranes, a precursor for steroid hormones (including testosterone, oestrogen, and cortisol), and necessary for producing vitamin D and bile acids that help digest fats. The liver manufactures most of the cholesterol your body needs, with the rest coming from dietary sources. Total cholesterol represents the sum of all cholesterol in your blood, including HDL (protective) and LDL (potentially harmful) fractions. While "high cholesterol" is often discussed as uniformly bad, the reality is more nuanced. Total cholesterol alone is a relatively crude measure—what matters more is the balance between protective HDL and harmful LDL, along with other factors like triglycerides, inflammation, and particle size. This is why a full lipid panel (as included in this test) is more informative than total cholesterol alone. Desirable total cholesterol is generally below 5.0 mmol/L, with levels between 5.0-6.2 mmol/L considered borderline and above 6.2 mmol/L considered high. However, these targets may be lower for people with existing cardiovascular disease, diabetes, or other risk factors. Total cholesterol should always be interpreted alongside HDL, LDL, non-HDL cholesterol, and triglycerides for meaningful assessment. Results outside the normal range may need a follow-up with your GP.

Low-density lipoprotein (LDL) cholesterol is often called "bad cholesterol" because elevated levels are strongly associated with the development of atherosclerosis—the buildup of fatty plaques in artery walls that can lead to heart attacks and strokes. LDL particles transport cholesterol from the liver to tissues throughout the body. When there's more LDL cholesterol than the body needs, these particles can penetrate the artery wall, become oxidised, and trigger an inflammatory process that forms atherosclerotic plaques. LDL is the primary target for cardiovascular risk reduction. The evidence that lowering LDL reduces heart attacks and strokes is overwhelming—it's one of the most robust findings in medicine. Both lifestyle changes (diet, exercise, weight loss) and medications (particularly statins) can effectively lower LDL. The lower the LDL, the lower the cardiovascular risk, with no apparent lower threshold below which further reduction stops being beneficial. Optimal LDL is below 3.0 mmol/L for most adults, but targets are lower for those at higher cardiovascular risk: below 2.5 mmol/L for moderate risk, below 1.8 mmol/L for high risk (e.g., existing cardiovascular disease, diabetes with complications), and some guidelines suggest below 1.4 mmol/L for very high risk individuals. LDL can be measured directly or calculated from other lipid values. Results outside the normal range may need a follow-up with your GP.

Non-HDL cholesterol is calculated by subtracting HDL cholesterol from total cholesterol (Total Cholesterol minus HDL = Non-HDL). It represents all the potentially atherogenic (artery-clogging) cholesterol in your blood—not just LDL, but also VLDL (very low-density lipoprotein), IDL (intermediate-density lipoprotein), and lipoprotein(a). This makes it a more comprehensive marker of cardiovascular risk than LDL alone. Non-HDL cholesterol is increasingly favoured by guidelines as a treatment target because it captures all harmful cholesterol fractions, doesn't require fasting for accurate measurement (unlike LDL calculated from the Friedewald equation), and is more reliably measured even when triglycerides are elevated. Some experts consider non-HDL the best single lipid marker for predicting cardiovascular risk. Desirable non-HDL cholesterol is below 4.0 mmol/L for most adults, with lower targets for those at higher cardiovascular risk (below 3.4 mmol/L for moderate risk, below 2.6 mmol/L for high risk). Non-HDL targets are typically 0.8 mmol/L higher than corresponding LDL targets. Because it's a calculated value, non-HDL is automatically available whenever total cholesterol and HDL are measured. Results outside the normal range may need a follow-up with your GP.

High-density lipoprotein (HDL) cholesterol is often called "good cholesterol" because higher levels are associated with reduced cardiovascular risk. HDL particles perform "reverse cholesterol transport"—they collect excess cholesterol from tissues and artery walls and transport it back to the liver for excretion. HDL also has anti-inflammatory, antioxidant, and anti-thrombotic properties that may contribute to its protective effects. Unlike LDL, where lower is better, higher HDL is generally desirable. However, the relationship between HDL and cardiovascular risk is more complex than originally thought. While low HDL is clearly associated with increased risk, drugs that raise HDL haven't consistently reduced cardiovascular events, suggesting HDL may be more of a marker than a direct cause of protection. HDL quality and function may matter more than quantity. For men, HDL below 1.0 mmol/L is considered low and is an independent cardiovascular risk factor. Levels above 1.5 mmol/L are associated with reduced risk. HDL is raised by regular aerobic exercise, moderate alcohol consumption, weight loss, smoking cessation, and a diet rich in healthy fats (olive oil, nuts, fatty fish). Very high HDL (above 2.3 mmol/L) is usually benign but occasionally indicates a genetic condition. Results outside the normal range may need a follow-up with your GP.

The Total Cholesterol to HDL ratio (TC: HDL) is calculated by dividing total cholesterol by HDL cholesterol. This ratio provides insight into the balance between harmful and protective cholesterol and is a useful indicator of cardiovascular risk. The ratio captures the proportion of your total cholesterol that is the protective HDL type—a low ratio indicates a favourable balance. The TC: HDL ratio is particularly useful because it integrates information from both total cholesterol and HDL into a single number. Someone with total cholesterol of 6.0 mmol/L might have very different cardiovascular risk depending on whether their HDL is 1.0 mmol/L (ratio 6.0, high risk) or 2.0 mmol/L (ratio 3.0, low risk). The ratio helps contextualise total cholesterol values. A TC: HDL ratio below 4.0 is desirable for men, with ratios below 3.5 considered optimal. Ratios above 6.0 indicate significantly elevated cardiovascular risk. Improving the ratio can be achieved by lowering total/LDL cholesterol (diet, exercise, statins), raising HDL (exercise, weight loss, smoking cessation), or both. The ratio should be interpreted alongside individual lipid values and other cardiovascular risk factors. Results outside the normal range may need a follow-up with your GP.

Triglycerides are the most common type of fat in the body. When you eat, your body converts calories it doesn't need immediately into triglycerides, which are stored in fat cells and later released for energy between meals. Triglycerides are transported in the blood within VLDL (very low-density lipoprotein) particles. Unlike cholesterol, triglyceride levels fluctuate significantly with food intake, which is why fasting is required for accurate measurement. Elevated triglycerides are associated with increased cardiovascular risk, particularly when combined with low HDL and small, dense LDL particles—a pattern often called "atherogenic dyslipidaemia" that's common in metabolic syndrome and type 2 diabetes. Very high triglycerides (above 10 mmol/L) can also cause acute pancreatitis. Triglyceride levels are strongly influenced by diet (especially refined carbohydrates, sugar, and alcohol), weight, physical activity, and metabolic health. Normal fasting triglycerides are below 1.7 mmol/L. Levels of 1.7-2.3 mmol/L are borderline high, 2.3-5.6 mmol/L are high, and above 5.6 mmol/L are very high. Triglycerides are often the most responsive lipid to lifestyle changes—reducing alcohol, losing weight, cutting refined carbohydrates and sugar, and increasing exercise can dramatically lower triglycerides. Omega-3 fatty acids (fish oil) also reduce triglycerides. Results outside the normal range may need a follow-up with your GP.

Vitamin B12 (cobalamin) is essential for DNA synthesis, red blood cell formation, and the maintenance of the nervous system. The body cannot produce B12—it must come from animal-derived foods (meat, fish, eggs, dairy) or supplements. B12 is absorbed in the small intestine with the help of a protein called intrinsic factor, produced by the stomach. Deficiency can occur due to inadequate intake (vegans, vegetarians), absorption problems (pernicious anaemia, coeliac disease, Crohn's disease, gastric surgery), or certain medications (metformin, proton pump inhibitors). Active B12 (holotranscobalamin) measures only the biologically available B12 that can be taken up by cells—approximately 10-30% of total B12. This makes it a more sensitive and earlier marker of B12 deficiency than total B12. Symptoms of B12 deficiency include fatigue, weakness, neurological symptoms (numbness, tingling, balance problems, cognitive changes), glossitis (sore tongue), and anaemia. Neurological damage from severe B12 deficiency can be irreversible if not treated promptly. Normal active B12 is typically above 37.5 pmol/L, with levels below 25 pmol/L indicating likely deficiency. Levels between 25-37.5 pmol/L are borderline and may warrant further investigation or a trial of supplementation, particularly if symptoms are present. B12 supplementation is safe, effective, and can produce dramatic improvement in deficient individuals. Results outside the normal range may need a follow-up with your GP.

Vitamin D is a fat-soluble vitamin that functions as a hormone in the body. Its most well-established role is regulating calcium and phosphate absorption from the gut and maintaining healthy bones—vitamin D deficiency causes rickets in children and osteomalacia (soft bones) in adults. Beyond bone health, vitamin D receptors are present in most tissues, and adequate vitamin D may influence immune function, muscle strength, mood, cardiovascular health, and cancer risk, though evidence for these effects varies. Vitamin D is primarily produced in the skin through sun exposure, with smaller amounts from diet (oily fish, fortified foods, egg yolks). In the UK, vitamin D deficiency is extremely common—particularly in winter months when sun exposure is insufficient for vitamin D synthesis. Risk factors for deficiency include limited sun exposure, dark skin, older age, obesity, malabsorption conditions, and spending most time indoors. Vitamin D status is classified as: deficient (below 25 nmol/L), insufficient (25-50 nmol/L), adequate (50-75 nmol/L), and optimal (above 75 nmol/L). Some experts recommend levels above 75 nmol/L for optimal health, particularly for bone health and muscle function. The UK government recommends all adults consider taking 10 micrograms (400 IU) of vitamin D daily, especially during autumn and winter. Higher doses may be needed to correct deficiency. Results outside the normal range may need a follow-up with your GP.