Homocysteine is an amino acid your body makes when it breaks down protein, and it clears it using vitamin B12, folate and B6. So a high level often means one of those is running low, even when your other results look fine. High homocysteine is also linked with heart disease and stroke, which makes it worth knowing early. The lab range is 5 to 15 µmol/L. Members can add a homocysteine test to their Baseline for $59 in the Vively app, or get it in the Longevity Panel ($199), from one fasting blood draw with results usually within a week.
The homocysteine test is an add-on for Vively members, and it's also in our Longevity Panel. You start with your Baseline Health Check.
Every marker in range? Get your $99 back. T&Cs apply.Want to save 25%? Try our 4-Month Reset insteadHomocysteine is an amino acid your body makes from methionine, which comes from the protein you eat. It is a short-lived middle step. Your body either recycles it back into methionine, which needs folate and vitamin B12, or turns it into another amino acid, cysteine, which needs vitamin B6. A homocysteine blood test measures how much is left over, in micromoles per litre (µmol/L).
When those vitamins are in short supply, or your kidneys clear it more slowly, homocysteine builds up in your blood.
A homocysteine test is useful for two reasons: it can flag a B12 or folate problem early, and it adds to your heart risk picture.
B12 results can sit in a grey zone, where the number looks borderline and doesn't match how you feel. Homocysteine rises when your cells are short of B12 or folate, so it helps show whether a borderline result is a real shortfall. Labs use it for exactly this when a B12 result is inconclusive.
Large population studies link high homocysteine with heart attack, stroke, blood clots and memory decline. The link with the heart is weaker than it first looked, though. Trials that lowered homocysteine with B vitamins did not cut heart attacks, and a 2017 Cochrane review found a small drop in stroke, of about 10%. So we treat a high result as a sign to look for the cause and to work on your other heart risks, rather than as a target on its own.
For adults, a typical lab range for homocysteine is about 5 to 15 µmol/L.
| Range | |
|---|---|
| Typical lab reference range (adults) | 5 to 15 µmol/L |
| Mildly raised | 15 to 30 µmol/L |
| Moderately raised | 30 to 100 µmol/L |
| Severely raised (rare) | Above 100 µmol/L |
Labs set their own ranges, so check the range on your report. Some labs use a lower upper limit. Levels rise a little with age and tend to be slightly higher in men. We don't publish a Vively optimal range for homocysteine yet. We look at where you sit in the range, your trend over time and your B12, folate and kidney results.
A high homocysteine most often points to low B12, low folate or reduced kidney function. Mild rises are common and often have a cause your practitioner can find.
Common causes:
Some people carry two copies of a common MTHFR gene variant. On its own this often causes little change, but it can push homocysteine up when folate is low. Very high levels, above 100 µmol/L, are rare and can come from inherited conditions such as homocystinuria, which need specialist care.
Low homocysteine is rarely a concern. It can show up when you take B vitamin supplements, and levels drop during pregnancy. If your result is below the lab range and you feel well, it usually needs no action.
Fast for 8 to 12 hours before the test if you can, with water allowed. A big protein meal can lift homocysteine for several hours.
Homocysteine makes most sense next to the markers that drive it.
| Pattern | What it can mean |
|---|---|
| High homocysteine, low or borderline B12 | Your cells may be short of B12, even if the B12 number looks close to normal. |
| High homocysteine with large red cells (high MCV) | Points towards low B12 or folate. Worth a GP review. |
| High homocysteine with low eGFR | Slower kidney clearance may be the cause. Your GP should look at kidney function. |
| High homocysteine with high TSH | An underactive thyroid can raise homocysteine. Recheck once thyroid is treated. |
| High homocysteine with high ApoB or Lp(a) | Your heart risks add up. Bringing ApoB and blood pressure down matters more. |
Most mild rises come down when you fix the nutrient behind them. Find the cause first, then make the change.
Retest 8 to 12 weeks after a change to see whether it has worked.
See your GP if your homocysteine is above 30 µmol/L, or if any raised result comes with:
A result above 100 µmol/L needs prompt medical review.
The homocysteine test is an add-on for Vively members, and it's also in our Longevity Panel with ApoB, ApoA1 and Lp(a). You start with your Baseline Health Check, which already covers your full blood count, kidney function and thyroid, then add homocysteine in the Vively app.
Your test referral is issued straight away when you order. You give one blood sample at one of 3,700+ partner collection centres, with no booking needed. Results come into your app, usually within a week, and a practitioner talks you through them and helps you plan any diet or supplement changes before a retest. Start with your Baseline.
Yes, if you can. Fasting for 8 to 12 hours, with water allowed, gives the most reliable result, because a large protein meal can lift homocysteine for several hours. A morning test after an overnight fast is easiest. Keep taking prescribed medicines and supplements unless your doctor says otherwise.
Only in some cases. Medicare funds homocysteine as part of a B12 work-up, when a lab adds it to an inconclusive B12 result or a doctor orders follow-up B12 testing for someone at risk. Outside those cases it's a private test. Through Vively it's a private add-on.
It's mildly raised. A result of 16 µmol/L sits just above the typical upper limit of 15. Mild rises are common and often come from low B12 or folate, kidney function or lifestyle. Check your B12, folate and kidney results with your practitioner, then retest after any change.
Yes, when low B12, folate or B6 is the cause. Levels usually fall within a few weeks of fixing the shortfall. In trials, though, lowering homocysteine with B vitamins did not reduce heart attacks. Use supplements to fix a real deficiency, chosen with your practitioner, not as heart protection on their own.
Usually not. Your homocysteine result already shows whether your folate pathway is coping, and the treatment is the same either way: enough folate and B12. The RCPA and RACGP advise against routine MTHFR testing, and it has no Medicare rebate. If your level is very high, your GP can look for other causes.
Retest about 8 to 12 weeks after you change your diet or start a supplement. That's long enough for levels to settle. If your result was normal and nothing has changed, there's no need to repeat it routinely.
How to get it: An add-on test for Vively members, and part of the Longevity Panel. Your test referral is issued straight away when you order. See how a blood test without a referral works.
Add-on test: Homocysteine Test
Related tests: Vitamin B12, Mean Cell Volume (MCV), eGFR, Lipoprotein(a)
The Baseline Health Check reads 70+ markers, then your dietitian turns your results into a plan. $99 a month, first test included.
Every marker in range? Get your $99 back. T&Cs apply.