Supplements: fill gaps, don't stack pills
A supplement fills a specific gap: it doesn't replace your plate, your sleep, or your training. Here are the ones with the best evidence-to-price ratio for your situation.
The essentials
Vitamin D3: Health Canada recommends a 400 IU daily supplement from age 51, and the Quebec winter, from November to March, lowers everyone's levels (Vitamin D3 page).
Creatine monohydrate: the best-documented performance supplement; Health Canada's benchmark: 3 to 5 g a day for at least 4 weeks, without loading (Creatine page).
Magnesium: useful when your diet falls short; the limit from supplements is 350 mg a day (Magnesium page).
Omega-3 (1-2 g EPA+DHA/day) if you're eating fatty fish less than twice a week.
Protein powder is a convenient food, not a supplement: useful for hitting your targets.
One new addition at a time, with 3-4 weeks to observe before adding the next.
Quality matters: simple ingredients, clearly labeled doses, third-party certification when possible.
These benchmarks also feed your personalized plan. Build my plan
Based on your goal
Choose your goal: here is what matters most for it.
Weight loss
- Protein powder to lock in 25-35 g per meal when your appetite is suppressed.
- Soluble fiber (psyllium) if constipation sets in on a GLP-1.
- A simple multivitamin can cover the basics when a smaller appetite means skipping whole food groups.
Performance
- Creatine, 3-5 g/day continuously, no need for a loading phase.
- Caffeine is the best-documented stimulant; study benchmarks and Health Canada's daily maximum (400 mg) are on the Caffeine page.
Focus & cognition
- Creatine and omega-3 have more cognitive evidence behind them than most pricey "nootropics."
- Caffeine remains the best-documented lever for focus; L-theanine softens it, on evidence that is still thin.
Sleep
- Magnesium if your diet falls short, without going over 350 mg a day from supplements (Magnesium page).
- Avoid taking melatonin continuously without guidance: useful occasionally (like for jet lag), not as a daily crutch.
- L-theanine (100-200 mg) in the evening quiets a racing mind without forcing drowsiness.
Energy
- Get ferritin and B12 checked before supplementing blindly: fatigue often has a measurable cause.
Longevity
- Vitamin D3 and omega-3: two basics with fair evidence, especially when intake is low.
- Creatine is gaining ground in research on cognition and muscle in aging adults.
Repair & recovery
- Hydrolyzed collagen (10-15 g) + vitamin C about 30-60 minutes before targeted rehab work.
- Zinc (15-30 mg) temporarily if your diet is low in meat or seafood.
Joints & mobility
- Collagen plus vitamin C before load-bearing exercise.
- Omega-3 at a sufficient dose (2 g EPA+DHA) for inflammatory discomfort.
Digestion & inflammation
- Psyllium: the best-tolerated fiber for regularity without irritation.
- Probiotics: the evidence is strain-specific, try one for 4 weeks and keep it only if you notice a clear benefit.
- Ginger has decent evidence for mild nausea; peppermint for digestive cramping.
Skin & appearance
- Collagen: an effect on elasticity in industry-funded trials, absent from independent trials (thin evidence).
- Omega-3 for dry or reactive skin.
Stress & calm
- Magnesium first: it's the most common deficiency during chronic stress.
- L-theanine (100-200 mg) softens caffeine's edge without causing drowsiness.
- Ashwagandha has interesting data on perceived stress, but avoid it without medical advice if you have a thyroid condition or are pregnant.
Libido & intimacy
- Zinc and vitamin D if you're low on either: both correlate with testosterone.
- Be wary of proprietary "T boosters": underdosed blends with weak evidence.
Recomposition & muscle gain
- Creatine monohydrate 3-5 g a day, every day, training or not: the best-documented supplement for strength and lean mass.
- Protein powder only if the plate doesn't hit the target: it's a convenient food, nothing more.
In detail
The hierarchy that matters
Plate, sleep, movement, then supplements: in that order.
A supplement fixes an identified gap: vitamin D because Quebec sunlight disappears for six months a year, magnesium because stress burns through it, omega-3 because fish rarely makes it onto the plate.
Stacking ten products without identifying the gaps just means paying good money for expensive urine. The question to ask before every purchase: "what specific gap am I filling, and how will I know if it's working?"
What the evidence actually supports
Five pages reach the strong-evidence level: creatine, caffeine, protein powder, psyllium, and iron when a deficiency is documented. Vitamin D, omega-3s, and magnesium have real but modest data, especially when you're low. The rest is thin, underdosed, or oversold: each page says so.
Timing and absorption: the details that change everything
A good supplement taken the wrong way does nothing for you. Vitamin D is fat-soluble: it absorbs best with a meal that has some fat in it.
Magnesium can be taken whenever suits you: spacing it from certain medications matters more.
Iron absorbs best on an empty stomach with vitamin C, but never with coffee, tea, or dairy, which block its absorption for about two hours. Creatine can be taken anytime: it's daily consistency that matters.
Zinc and iron compete with each other: space them out if you're taking both.
Herbal supplements: useful, but not harmless
Some herbal supplements have real evidence behind them: ashwagandha for perceived stress and sleep, rhodiola for mental fatigue, ginger for nausea.
But "natural" doesn't mean "no effect", and it doesn't mean no interactions or contraindications either.
Ashwagandha affects the thyroid, St. John's wort interacts with a long list of medications, licorice root raises blood pressure.
The rule of caution: one herb at a time, at the labeled dose, checking interactions with a healthcare professional if you're on medication, and never during pregnancy or breastfeeding without professional advice.
Interactions and caution
"Supplement" doesn't mean "harmless": St. John's wort interacts with numerous medications, high-dose omega-3s thin the blood, long-term zinc use throws off copper levels, and iron taken without a measured deficiency can build up.
If you're on medication, a five-minute check with a healthcare professional can prevent real mistakes. And as a reminder: nothing on this page replaces the advice of a healthcare professional who knows your history.
Choosing quality products
The supplement market is loosely regulated: the actual dose doesn't always match the label.
Reliable signs to look for: a Natural Product Number (NPN) from Health Canada on the label, simple ingredients rather than "proprietary blends" that hide the doses, independent third-party certification (NSF, Informed Choice) for athletes, and a reasonable price: generic creatine monohydrate does exactly the same job as the "premium" version at three times the cost.
How to introduce a new supplement
One new supplement at a time, at the standard dose, for 3-4 weeks, with a success criterion defined in advance ("I fall asleep in under 30 minutes," "no more nighttime cramps"). No measurable effect?
Drop it and move to the next one. This discipline avoids two traps: paying for products that do nothing, and crediting the wrong product for an effect that actually came from somewhere else.
Your cabinet, and your budget, will stay a lot healthier.
Common mistakes
- Starting three supplements the same week: impossible to tell what's doing what.
- Buying underdosed "all-in-one" proprietary blends instead of simple ingredients.
- Supplementing iron without a blood test to confirm you're actually low.
- Taking vitamin D on an empty stomach: it's fat-soluble and needs fat to absorb.
- Assuming a "natural" product is automatically risk-free and interaction-free.
- Forgetting that protein powder counts toward your total intake: it's food.
43 supplements, and what the label does not say
Each sheet says what it is, the forms found on shelves, the published benchmarks, what to space out, what to flag, and its level of evidence, without flattery. Sorted from the strongest evidence to the thinnest; the needs below filter the list. No price, no brand: information, to choose before buying anywhere.
The best-documented stimulant in sport; the issue on store shelves is the dose per serving, stacking with coffee, and sleep.
The best-documented performance supplement, whose reference form remains the monohydrate despite the forms sold as superior.
A supplement not to take blindly: useful in documented deficiency, debatable otherwise, and highly dependent on what goes with it at the meal.
A dehydrated food more than a supplement: what counts is the day's total, the leucine and what the label does not measure.
The best-studied soluble fibre, with a regulated health claim on cholesterol, provided you add plenty of water.
An Ayurvedic root sold for stress and sleep, whose trials rest on specific standardized extracts, with liver and thyroid signals you should know about.
A group of vitamins sold for energy, where the real issues are B12 in deficiency and B6 at high doses.
A plant alkaloid nicknamed "natural metformin" online, whose effect on blood sugar is real but fragile, and whose interactions are many.
An amino acid that loads muscle with carnosine over weeks; harmless tingling, and a one-off dose before training does nothing.
These sheets also feed the site assistant and your personalized plans. They do not replace the advice of a health professional.