Supplements A to Z
Every supplement we have reviewed: what it is, what the trials show, the risks and the medicines it interferes with, and how it compares with lifestyle changes and medicines.
How to read these pages
Each page is a full summary of the evidence for one supplement, written by Dr. French's team from the published research, with references. We grade how sure the evidence is, and we say so when it is weak.
Supplements we don't recommend get the same detail, with the reason.
These pages are general information for adults in Canada. Whether a supplement is right for you depends on your medicines, your health and what you already take.
Supplement Check
Not sure what you need?
The pages show how much there is to check. Our Supplement Check does that for you: $59 when it opens, anywhere in Canada, and your report arrives within 3 working days. Coming soon. The Supplement Check and the Online Health Assessment open once our safety testing is complete.
All supplements
A
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Age-50+ multivitamin (iron-free) | For women 65+ and men 60+ who do not smoke: small benefit on memory tests, low cost, low risk. No benefit on heart disease, stroke or death. | Part of the Supplement Check |
| Alpha-GPC | No ADHD trial; a study of 12 million Korean adults linked it with more strokes. Never with heart disease or narrowed arteries. | We don't recommend it |
| AREDS2 eye formula | Any macular degeneration, including early drusen, or other diagnosed eye disease: you should be on it (the trial benefit, 78 fewer progressions per 1,000 over about 5 years, is for intermediate macular degeneration). No eye disease: a personal choice; we don't know whether it prevents anything. | Should be on it with eye disease ยท otherwise a personal choice |
| Ashwagandha | Implausibly large pooled effects, low certainty, and reports of liver injury. | We don't recommend it |
B
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| B-complex | Gives no energy or calm unless you are short of a B vitamin, and 8 in 10 sold in Canada contain 10 mg or more of vitamin B6. | We don't recommend it |
| Berberine | Lowers blood sugar a little (about 0.4%), never tested on heart or kidney outcomes, and blocks the enzymes that clear many medicines. | We don't recommend it |
| Biotin (vitamin B7) | No evidence it helps hair or nails without a deficiency, and high doses make blood tests wrong, including the heart test used for chest pain. | We don't recommend it |
C
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Calcium | Food first. A supplement only for a measured shortfall, 500 mg or less. Never sold "for the arteries". | Part of the Supplement Check |
| Citicoline | Did no better than placebo in the one randomised ADHD trial; $25โ40 a month for an effect no one has shown. | We don't recommend it |
| Cluster dextrin | A price premium with no proof it beats ordinary maltodextrin in sport. | We don't recommend it |
| Creatine monohydrate | 3โ5 g a day for most adults with healthy kidneys. Adds muscle and strength with training; small benefit without. | Part of the Supplement Check |
E
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Essential amino acids (EAA) | Second line, only when meals fall short and you cannot take whey or another protein powder. | Part of the Supplement Check |
F
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Folic acid 0.4 mg | Before and in early pregnancy. A previous neural-tube defect needs a higher prescription dose. | Part of the Supplement Check |
H
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| HMB | No effect on lean mass or strength in trained young adults. | We don't recommend it |
I
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Iron | Only when iron studies (not ferritin alone) show you are low. Our products are iron-free by default. | Part of the Supplement Check |
| Isomaltulose (Palatinose) | During exercise it made cyclists slower and caused cramps; no benefit before exercise. | We don't recommend it |
L
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| L-theanine | May help sleep quality a little where a busy mind is the problem; safe. Not for ADHD symptoms. | A personal choice |
| Lavender oil (Silexan 80 mg) | The best-studied supplement for anxiety, but the trials are maker-funded and the product is not confirmed on the Canadian market. | Not offered yet: availability in Canada not confirmed |
M
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Magnesium bisglycinate | 400 mg at night for poor sleep, with normal kidneys: a small benefit, low certainty. Bisglycinate only: the other forms loosen the bowels. | Part of the Supplement Check |
| Magnesium threonate | Small company-funded trials, three times the price of [link:bisglycinate|/pages/supplement-magnesium-bisglycinate], never compared with it. | We don't recommend it |
| Melatonin | A body-clock signal, not a sleeping pill: for a late body clock, jet lag, and prolonged-release 2 mg at 55+. Not for ordinary insomnia under 55. | Part of the Supplement Check |
N
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Niacin (nicotinic acid) | Improves cholesterol numbers but did not prevent heart attacks, strokes or deaths in large trials, and raised the risk of diabetes, infection, bleeding and liver damage. | We don't recommend it |
| NMN and NR ("NAD boosters") | Raise NAD+ in the blood but improved no clinical outcome. Never in Parkinson disease. | We don't recommend it |
O
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Omega-3 (fish oil; algal for vegans) | When you eat oily fish less than twice a week. Not for heart prevention: 1 g a day did not prevent heart attacks. | Part of the Supplement Check |
P
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Peppermint oil, enteric-coated | Worth trying for irritable bowel once warning signs are excluded. | Part of the Supplement Check |
| Phenylalanine | Did nothing or helped briefly in small ADHD trials; dangerous in phenylketonuria and with MAOI antidepressants. | We don't recommend it |
| Phosphatidylserine | One trial in 36 children; no adult evidence for focus, memory or mood. | We don't recommend it |
| Probiotics | During antibiotics (prevents C. difficile, 1 in 42 helped). For irritable bowel, low to very low certainty. | Part of the Supplement Check |
| Protein powder | Only when meals fall short of your protein target. A powder is just a convenient food. | Part of the Supplement Check |
R
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Rhodiola | Contradictory trials, all at high or unclear risk of bias. | We don't recommend it |
S
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Saffron | Lowered self-rated low mood in small trials, but not when doctors rated mood blind. Often faked; avoid in pregnancy. | We don't recommend it |
| SAMe | Low-quality evidence, high cost, and reports of mania. | We don't recommend it |
| Soluble fibre (barley first) | Lowers LDL a little, and helps blood sugar when it is raised. Barley beta-glucan first; oat beta-glucan if avoiding gluten; psyllium only with published heavy-metal results. | Part of the Supplement Check |
| Sport carbohydrate (glucose + fructose) | For events over 2 to 2.5 hours: the one sport product with a real performance effect. With our game-day guide. | Part of the Supplement Check |
| St John's wort | Works for depression, but clashes with the pill, warfarin, blood thinners, transplant drugs and many others. | We don't recommend it |
| Sulforaphane (with active myrosinase) | For work exposure to fumes or metals, and smokers: raises excretion of some air pollutants. Stopping the exposure comes first. | Part of the Supplement Check |
T
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Tart cherry | Optional for athletes after very hard sessions; small benefit, low certainty. | A personal choice |
| Tyrosine | The only ADHD study lost its benefit within 6 weeks; can raise blood pressure with MAOI antidepressants. | We don't recommend it |
V
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Vitamin B12 | When a test shows low, or a cause exists (metformin, acid blockers, vegan diet). Not on age alone. | Part of the Supplement Check |
| Vitamin B6 | Hidden in magnesium, multivitamin, B-complex and energy products; no proven benefit without a deficiency, and the doses add up to a risk of nerve damage in the hands and feet. | Only when prescribed |
| Vitamin D3 | 1,000 IU October to April for those with little sun or a low level. In Canada skin makes almost none in winter. | Part of the Supplement Check |
Z
| Supplement | What it is mostly bought for | Status |
|---|---|---|
| Zinc | Only when intake is low (vegan, little meat) or a level is measured low. Counted against the upper limit with everything else. | Part of the Supplement Check |
Disclosure of financial interest
White Pine Medical earns money from products bought through our Fullscript dispensary. Dr. French's Code of Ethics requires him to tell you this. You do not have to buy anything from us: every product is named by its ingredient and dose so you can buy it at any pharmacy, and the advice is the same wherever you buy it, or if you buy nothing.