Supplement plan
A ten-item morning stack and a two-item evening stack, with each item rated by the strength of its evidence. Choose what you take, set your doses and see your schedule, safe limits and the cautions that apply to you.
Learn the plan
This is not a prescription. More supplements isn't better. Most healthy people who eat well need few of them, and several items here have limited evidence. Choose only the ones you have a reason to take.
Talk to your GP or pharmacist first if you take any regular medicine, especially warfarin or other blood thinners, blood pressure tablets, nitrates, thyroid medicine, antibiotics or diabetes medicine. Also ask first if you have kidney disease, liver disease or a heart rhythm problem, are pregnant or breastfeeding, are under 18, or have surgery coming up.
Use your blood tests. Vitamin D, vitamin B12 and magnesium needs vary. Set doses from your results with your doctor instead of copying someone else's.
Choose products listed with the TGA (look for an AUST L or AUST R number on the label), and check the label for the actual amount of each active ingredient. Stop and see your doctor if you get an unusual reaction.
Typical doses from the plan. Evidence ratings reflect human trials, and "limited" means small, short or mixed studies.
| Supplement | Dose | What the evidence says | Evidence |
|---|---|---|---|
| Multivitamin | 1 capsule with food | Fills small gaps in B-vitamins and trace minerals. Little proof of benefit if you already eat well. | Limited |
| Omega-3 fish oil | Check the label for EPA + DHA | Lowers triglycerides at higher doses. In healthy people, large trials found no clear reduction in heart events. Over 1 g a day of EPA + DHA was linked to more atrial fibrillation. | Limited |
| Vitamin D3 | Set by blood testPlan average 4,000 IU, see limits | Corrects deficiency. In healthy adults, a large trial of 2,000 IU a day found no fewer fractures, cancers or heart events. | Well established if low |
| Vitamin K2 (MK-7) | 90 to 120 mcg | Helps direct calcium to bone. Evidence for bone and artery benefits is modest. Interacts with warfarin. | Limited |
| Vitamin B12 | 500 mcgAdjust by blood test | Treats and prevents deficiency, which is more common in vegans, older adults and people on metformin. | Well established if low |
| N-acetylcysteine (NAC) | 600 to 1,200 mg, split in two | Builds glutathione. Proven as a paracetamol overdose antidote at medical doses. Benefit as an everyday supplement is unproven. | Limited |
| Aged garlic extract | 300 mg | Lowers systolic blood pressure mainly in people with high blood pressure. Trials used 480 to 960 mg a day, and 240 mg didn't work. | Limited |
| CoQ10 | 100 mg | Mixed results for blood pressure and for statin muscle aches. Generally well tolerated. | Limited |
| Creatine monohydrate | 3 g | Improves strength and lean mass, especially with resistance training. Safe in healthy people at 3 to 5 g a day. Possible cognitive benefit is still emerging. | Well established |
| Collagen peptides | 5 g | Small improvements in skin and joint symptoms in some trials. Study quality varies. | Limited |
Where the plan overstates. The source plan describes fish oil as safely reducing "body-wide inflammation". Its effect on inflammation is modest, so we've rated it conservatively. Likewise, vitamin D at 4,000 IU a day equals the US and EU upper limit but exceeds Australia's. See "Safe limits".
Take both 30 to 60 minutes before bed.
| Supplement | Dose | What the evidence says | Evidence |
|---|---|---|---|
| Magnesium citrate | 300 mg elemental magnesiumCheck the label shows elemental | Corrects low intake. It also draws water into the bowel, which helps regularity. Evidence that it improves sleep is limited. | Well established for low intake |
| Glycine | 3 to 5 g | 3 g before bed improved sleep quality and daytime sleepiness in small trials of people with poor or restricted sleep. It lowers core body temperature, which is a natural sleep signal. | Limited |
Magnesium adds up. If you use the electrolyte mix, its small amount of magnesium (about 10 mg a serve) counts towards your total. The upper limit for supplements is 350 mg of elemental magnesium a day.
Your body makes glutathione, its main internal antioxidant, from three amino acids. Glycine and cysteine are the limiting ones, and NAC supplies cysteine. GlyNAC is the name for taking glycine and NAC together, with NAC in the morning and glycine at night in this plan.
What the research actually is. The headline results come from one research group at Baylor College of Medicine. Their randomised, placebo-controlled trial (Kumar et al., 2023) gave GlyNAC to 12 older adults and placebo to 12 for 16 weeks. A separate dose-ranging trial of 114 healthy older adults found GlyNAC safe and well tolerated, but the glutathione rise was mainly in people with high oxidative stress. These are small studies and need repeating by independent teams.
Dose gap. The Baylor trials used doses based on body weight that work out to several grams of each amino acid a day for an average adult. This plan uses 600 to 1,200 mg of NAC and 3 to 5 g of glycine, which is lower. Benefits seen in the trials can't be assumed at these doses.
The 18 reported benefits, rated
| Target | What the research shows | Evidence |
|---|---|---|
| 1. Heart and vessels | Baylor trial reported better blood vessel function and lower systolic blood pressure. | Limited |
| 2. Brain and thinking | A small pilot study reported better memory and cognition in older adults. | Limited |
| 3. Liver | NAC protects the liver in paracetamol overdose at medical doses. Benefit for everyday liver health is unproven. | Limited |
| 4. Kidneys | Human studies of NAC for kidney protection are mixed. | Limited |
| 5. Thyroid | Based on laboratory mechanisms only. No human GlyNAC trials. | Speculative |
| 6. Inflammation | Trial reported lower IL-6, TNF-alpha and hs-CRP. | Limited |
| 7. Oxidative stress, mitochondria | Trial reported lower oxidative stress markers and better mitochondrial markers. | Limited |
| 8. Homocysteine | Plausible mechanism. Human data are limited. | Limited |
| 9. Detox, heavy metals | Mostly laboratory and animal work. | Speculative |
| 10. Sleep | Glycine alone, 3 g before bed, improved sleep quality in small trials. It wasn't tested as GlyNAC. | Limited |
| 11. Muscle strength | Trial reported better grip strength and faster walking speed. | Limited |
| 12. Body composition | Trial reported smaller waist size. Fat and muscle changes are preliminary. | Limited |
| 13. Insulin sensitivity | Trial reported improved insulin resistance markers. | Limited |
| 14. DNA damage | Trial reported lower DNA damage markers. What this means for health is unknown. | Limited |
| 15. Exercise capacity | Trial reported improved exercise capacity measures. | Limited |
| 16. Immune function | Plausible, since immune cells need glutathione. No GlyNAC trial. | Speculative |
| 17. "Reversing aging hallmarks" | One small trial in older adults with a BMI over 27. "Reversal" overstates what was measured. | Limited |
| 18. Antioxidant reserve | Glutathione rose in trials. The rise was mainly in people with high oxidative stress. | Limited |
- Fat-soluble items with food. Take vitamin D3, vitamin K2, CoQ10 and omega-3 with breakfast or lunch. Fat in the meal helps absorption. B-vitamins and the multivitamin can go with the same meal.
- Split the NAC. One dose with your early electrolyte drink and one with breakfast. Food proteins help protect the stomach from NAC's acidity, and two doses give a steadier supply of cysteine.
- Creatine and collagen in your morning shake or coffee. Either works. For creatine, the daily habit matters more than the exact time.
- Magnesium and glycine before bed. Take them 30 to 60 minutes before sleep.
- Drink plenty of water. NAC and magnesium both rely on good hydration. See the hydration plan.
- Separate from some medicines. Magnesium and multivitamin minerals can reduce absorption of thyroid medicine and some antibiotics. Leave 2 to 4 hours between them and ask your pharmacist about your medicine.
| Nutrient | Upper limit or key fact |
|---|---|
| Vitamin D | Australia (NHMRC): 80 µg, or 3,200 IU, a day for adults. USA (Institute of Medicine) and Europe (EFSA): 100 µg, or 4,000 IU. Limits count all sources, including your multivitamin. |
| Magnesium | 350 mg a day of elemental magnesium from supplements (NHMRC and USA). Higher doses commonly cause diarrhoea. Kidney disease raises the risk. |
| Fish oil (EPA + DHA) | No Australian upper limit, but a 2021 meta-analysis of 7 trials linked more than 1 g a day to a 49% higher atrial fibrillation risk, and 1 g or less to 12% higher. |
| Vitamin K2 | No upper limit set, but it works against warfarin even at low doses. It isn't thought to affect newer blood thinners such as apixaban or rivaroxaban. |
| Vitamin B12 | No upper limit set. Excess is generally excreted. |
| NAC | Oral doses of 600 to 1,200 mg a day are typical. Common side effects are nausea, diarrhoea and a sulphur smell. Can strengthen nitrates and cause low blood pressure and headaches. |
| Creatine | 3 to 5 g a day has been studied for years in healthy adults with no kidney harm. It raises blood creatinine, which can confuse kidney tests, so tell your doctor. |
| Aged garlic, fish oil | May add to the effect of blood thinners. Tell your surgeon or dentist before procedures. |
| CoQ10 | Case reports of weaker warfarin effect, though one controlled trial found no change. Treat as a possible interaction. |
How this page was checked
What we checked, and what we changed
Each item's dose, claim and safety note was compared with published trials, official nutrient reference values and drug interaction information. Where a claim from the original plan was stronger than the evidence, we softened it and tagged it.
Vitamin D: the plan's 4,000 IU average equals the US and EU upper limit but is above Australia's 3,200 IU. In healthy adults who aren't deficient, a large trial (VITAL) found no benefit for fractures, cancer or heart events. The planner starts at 1,000 IU and checks your total against all three limits.
Fish oil: "triple strength" softgels often contain around 1 g or more of EPA + DHA each, so two can pass 1 g a day. Check the label. A 2021 meta-analysis linked doses above 1 g a day to more atrial fibrillation.
Aged garlic: the plan's 300 mg sits between a dose that didn't lower blood pressure (240 mg) and one that did (480 mg) in an Australian trial of people with high blood pressure.
GlyNAC: 18 benefits were rated individually. Most come from one research group's small trials, and a few have no human trials. "Speculative" means a mechanism without human evidence.
Our judgement Ratings of "well established", "limited" and "speculative" are our summary of the evidence, not an official grading. The multivitamin, collagen and CoQ10 ratings reflect small or mixed trials. This is general information, not medical advice.
Sources and further reading
NHMRC, Vitamin D: nutrient reference values for Australia and New Zealand
NIH Office of Dietary Supplements, Vitamin D fact sheet
VITAL trial findings: vitamin D and omega-3 in healthy adults
Circulation (2021): marine omega-3 supplementation and atrial fibrillation, a meta-analysis
Kumar et al. (2023): GlyNAC in older adults, a randomised clinical trial
Frontiers in Aging (2022): glycine and NAC dose-ranging trial in healthy older adults
Bannai et al. (2012): glycine and sleep in sleep-restricted volunteers
Routines and protocols that tie the plan together.