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What’s worth taking? How much do you need? Start with your question, explore the evidence, then choose what fits.
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A useful place to start
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From your first protein powder to the small print on a label.
Compare powders, plan your intake and find an option that suits your stomach.
The most useful protein option is one that fits your diet, is tolerable, and helps meet an individually agreed nutrition plan. There is no established evidence that one retail protein powder is the best choice for everyone using a GLP-1 medicine. A powder can be a convenient food ingredient; it does not replace your medicine, a balanced diet or clinical care.
Casein and whey are both milk proteins. Choose according to your food needs, tolerance, preferred texture and budget; there is no general requirement to own a daytime whey and a separate bedtime casein. The idea of faster and slower digestion is useful context, but it does not settle which product will produce better results for you.
Whey and collagen are different protein sources, so equal grams on a label do not make them interchangeable. If your main aim is to add a suitable protein source to support a resistance-training diet, whey or an appropriate plant alternative is a more direct starting point than collagen alone. A whey–collagen blend needs its own label assessment.
Multiply the appropriate body weight in kilograms by a suitable protein factor in grams per kilogram per day. The multiplication is easy; choosing the factor and the weight basis requires context. A calculator cannot infer your medical history, training demands, appetite or whether current body weight is the right input.
Resistance training and an adequate overall diet are the foundation for maintaining strength through the menopause transition. Protein powder can help fill a defined food-intake gap. Creatine monohydrate has some direct research in postmenopausal women, but the average effects are modest or mixed, and it is not an automatic prescription or a treatment for menopause symptoms.
Your protein needs depend on your health, body size, age, activity and overall eating pattern. General New Zealand reference values and sports nutrition targets answer different questions. A number intended for a healthy adult who trains regularly should not be applied automatically to someone with kidney disease, poor appetite or a medically managed weight-loss plan.
Protein powder is a food product, not a universal number of shakes. Start with the protein you get from ordinary meals, then use the current label to decide whether a powder is a practical way to fill a specific gap. The amount of powder in a scoop is not automatically the amount of protein in that scoop.
There is no single protein powder that is best for every sensitive stomach. Start by distinguishing a possible allergy from digestive discomfort, then examine the exact formula, amount, mixing liquid and timing. Changing from whey to plant protein, isolate or collagen does not guarantee that symptoms will improve.
A protein shake and a meal replacement can look similar, but they do different jobs. A protein powder is primarily a convenient source of protein. It may provide little carbohydrate, fat, fibre or micronutrients when mixed with water. A product represented as a formulated meal replacement in New Zealand must meet specific composition rules, yet it is still designed to replace one or more meals rather than the whole diet.
Choose between whey isolate and concentrate using the finished product's protein amount, lactose information, ingredients, taste and price. Isolate can provide more protein in less powder, but a higher concentration does not establish better muscle gains or suitability for every person. Both are milk-derived ingredients.
Whey and suitably chosen plant proteins can both help meet everyday protein needs. Collagen has a different amino-acid profile and should not be treated as an equivalent sole protein source for a muscle-focused eating plan. The most useful choice depends on your diet, allergies, usual intake, taste preferences and budget, rather than the number of claims printed on a tub.
Understand creatine, pre-workout and hydration before building your routine.
Beta-alanine is a longer-term supplementation strategy for particular high-intensity exercise demands, not an instant stimulant. It is not necessary for every gym session. Tingling after a serving does not prove that the amount is appropriate or that the workout will improve.
Caffeine can improve performance for some people in some exercise settings, but a pre-workout is not a reason to chase the largest possible dose. Count the milligrams from every source, start with the lowest exposure likely to be useful, and protect sleep. The right choice depends on body size, the task, timing, personal response, medicines and health context.
Creatine and a pre-workout can appear in the same routine, but whether the combination is appropriate depends on every ingredient and the total amount consumed. “Pre-workout” is a product category, not a standard formula. Check whether it already contains creatine, how much caffeine it supplies and what else you take that day.
Citrulline malate may improve some exercise outcomes in some settings, but findings are mixed and a larger number on a label does not establish a better workout. Check whether the product contains L-citrulline or citrulline malate, how much is declared and whether any ratio is clearly defined.
Women can consider creatine monohydrate for relevant training goals, but no single recommendation covers every age, health condition or life stage. Research includes women, although many studies are small and results differ by outcome. A product does not need a women-specific label to contain creatine monohydrate, and that label does not prove a special benefit.
Loading is optional. A larger short-term intake raises muscle creatine stores more quickly; a lower daily approach does so more gradually. If there is no particular reason to prioritise speed, the simpler routine may be easier to follow and tolerate.
Creatine monohydrate is a well-studied sports supplement for repeated high-intensity exercise and resistance training. Research commonly uses 3–5 g daily, with an optional loading phase. It is not a stimulant, a protein powder or a substitute for training. The response varies between people, and whether it is worth using depends on the job you want it to do.
BCAAs are three of the nine essential amino acids. An EAA supplement includes the wider essential set, but neither product is automatically necessary when your diet already provides enough suitable protein. Start by checking your meals, training and actual problem before deciding which tub to buy.
There is no single litre target or electrolyte recipe that fits every walk. Your fluid and sodium needs change with route length, weather, pace, body size, clothing, access to safe water, food carried and individual sweat losses. Plan the whole trip first. An electrolyte product can be useful in some long, hot or high-sweat situations, but it does not replace water access, food, weather decisions or an emergency plan.
An electrolyte drink is optional for many ordinary gym sessions. It becomes more relevant when sweat losses are substantial, exercise is prolonged, conditions are hot, or you need to recover between closely spaced sessions. Focus on what you need to replace, in what conditions and over what time. A drink saying “hydration” on the front does not answer those questions.
Glutamine is not a routine requirement for a healthy adult's gym programme. Research about a particular gut condition or a laboratory marker does not establish that adding glutamine to an adequate diet builds more muscle, repairs everyone's gut or prevents illness.
HMB is not a default requirement for a gym programme. Its evidence varies by population, training programme, formulation and outcome. Findings in a person recovering from illness cannot be transferred directly to a healthy trained adult, and an acute muscle-protein measurement cannot guarantee long-term strength or muscle gain.
Choose a pre-workout by its disclosed ingredients, your total caffeine intake and the time you train. Decide first what you want it to do. Feeling stimulated, consuming fluid, supplying exercise fuel and taking a particular researched ingredient are different jobs. A product with more ingredients does not automatically do any of them better.
Oral rehydration solution (ORS), sports drinks and electrolyte powders can all contain fluid, carbohydrate and salts, but they are not interchangeable. ORS is used for illness-related fluid and salt loss under product and health guidance. Sports drinks are formulated around exercise. An “electrolyte” powder can vary widely, so its name alone does not tell you its sodium, carbohydrate, intended use or suitability.
Choose a pre-workout by the actual session and the exact label, not by whether the tub promises intensity. A caffeinated product may fit some people’s earlier high-intensity sessions. A stimulant-free product may fit later training or someone limiting caffeine. Neither category guarantees a better workout, and “stimulant-free” does not automatically mean medically suitable, fully disclosed or low risk.
Food first, useful context and clear limits for common nutrient questions.
Most healthy New Zealand adults eating a varied diet do not need a multivitamin “just in case.” Health New Zealand says supplements do not compensate for a poor diet and are usually a worse use of money than nutritious food unless a healthcare provider identifies a reason. Specific nutrients can be appropriate in defined situations, such as folic acid and iodine around pregnancy, B12 for vegan diets, vitamin D for higher-risk people, or iron after testing. A broad formula is not automatically the right tool.
Health New Zealand recommends a 0.8 mg (800 microgram) folic-acid tablet each day for people at low risk of a neural-tube-defect-affected pregnancy, starting at least four weeks before conception and continuing through the first 12 weeks of pregnancy. Some people need a prescribed 5 mg tablet because of their history, medicines or medical conditions. Ask a midwife, doctor or nurse practitioner which pathway applies; do not choose the high dose yourself.
A greens powder is not a serving-for-serving replacement for vegetables and fruit. It may provide selected vitamins, minerals or plant ingredients in a convenient drink, but usually contains much less food mass and fibre, and it cannot recreate the variety of a meal. Start by identifying the problem, whether it is travel, taste, low intake or a diagnosed nutrient gap. Then check whether the exact label addresses it.
Low-iodine soil does not mean every New Zealander needs an iodine supplement. Most people should first look at reliable food sources: commercially made bread, milk products, eggs and seafood. Pregnancy and breastfeeding are different: Health New Zealand recommends a registered iodine-only tablet providing 150 micrograms daily alongside food sources. Confirm pregnancy supplements with your midwife, doctor or nurse practitioner.
Do not start iron just because you feel tired. Girls and women have a higher risk of low iron because of menstrual blood loss, and requirements rise in pregnancy. But fatigue, hair shedding, headaches and poor exercise tolerance have many causes. Health New Zealand recommends blood testing and investigation of the cause; if iron is low, a clinician can choose a dose, form and duration and check whether it worked.
Neither magnesium glycinate nor magnesium oxide is universally best. NIH's evidence review says oxide is generally less bioavailable than several more soluble forms. Glycinate may be easier for some people to tolerate, yet direct high-quality evidence that it is always better absorbed or better for sleep is limited. Compare elemental magnesium per daily dose, your reason for taking it, gut response, medicines and price.
For most healthy adults, start with fish and a varied diet rather than assuming a fish-oil capsule is necessary. Health New Zealand recommends fish or seafood regularly, and the Heart Foundation suggests two to three portions weekly, including oily fish. If you do not eat fish, algae oil can provide DHA and sometimes EPA. Compare the actual EPA plus DHA per daily serving, not the large “fish oil” number.
Some specific probiotic strains can reduce antibiotic-associated diarrhoea, but “a probiotic” is not one interchangeable treatment. Benefit depends on strain, dose, population, antibiotic setting and when it is started. An outpatient meta-analysis found diarrhoea in 8.0% of probiotic users versus 17.7% of controls, but trials varied and the result cannot be applied to every product on a New Zealand shelf.
New Zealand's low-selenium soils do not prove that you are deficient. Medsafe reports that animal-feed practices and imported foods such as wheat and legumes help most New Zealanders reach around recommended intake. New Zealand dietary supplements must not recommend more than 150 micrograms of selenium per adult daily dose, and selenium has a relatively narrow margin between adequacy and excess.
People eating a vegan diet need a reliable source of vitamin B12 from fortified food, a supplement, or both. Fruit, vegetables, grains, legumes and ordinary fermented foods do not reliably supply active B12. Health New Zealand advises daily B12-fortified foods and says a supplement may be needed when these are not eaten regularly. Pregnancy, breastfeeding, neurological symptoms or suspected malabsorption require prompt clinical advice.
Vitamin C is essential, and deficiency impairs health, but routine supplements do not stop most people catching a cold. In Cochrane trials, regular supplementation modestly shortened cold duration (about 8% in adults and 14% in children) without meaningfully reducing cold incidence in the general population. A subgroup exposed to brief extreme physical stress appeared to have fewer colds, but this does not establish a benefit for ordinary gym training.
Most New Zealand adults should not assume they need a vitamin D supplement every winter. Start with your risk factors: where you live, how much time you spend outside, skin colour, clothing, medicines and health conditions. Health New Zealand identifies people with little sun exposure, naturally very dark skin, extensive skin covering, some absorption problems and some people in the South Island as having greater risk of low vitamin D. A clinician can decide whether advice, supplementation or testing fits your situation.
Zinc deficiency can lower testosterone, but extra zinc has not been shown to reliably “boost” testosterone in zinc-replete people. A 2023 systematic review found that baseline zinc/testosterone status, dose, form and duration changed results; only eight of its 38 included studies were clinical. If you have symptoms of low testosterone, use a clinician-led assessment; a zinc product cannot diagnose the cause, and one hormone result needs timing and clinical context.
Practical reading on sleep, weight management, collagen and recovery.
Ashwagandha is not a general-purpose stress, sleep, testosterone or performance treatment. NCCIH's evidence and safety review says some preparations may help stress or insomnia, while studies are small and heterogeneous and long-term safety is uncertain. Rare liver injury has been reported, and the herb should be avoided in pregnancy and breastfeeding and used cautiously with thyroid, immune, blood-pressure, diabetes, sedative and seizure medicines.
Collagen research reports some promising skin and joint outcomes, but the results are uneven and cannot be transferred automatically to every collagen powder. The product studied, the people taking it, the outcome measured, study quality and funding all matter. A trial about skin elasticity does not establish cartilage repair, and a joint-pain result does not establish muscle-building equivalence to whey.
A workable fat-loss plan combines an appropriate eating pattern, physical activity and ongoing support. Supplements are not a requirement. The plan should protect nutritional adequacy and fit your health, preferences, work and family life. It should also explain what happens after the initial weight change.
Magnesium is not an established treatment for chronic insomnia. A 2021 systematic review found only three small randomised trials in 151 older adults. Sleep-onset time was shorter by about 17 minutes in the pooled estimate, while total sleep time was not significantly improved. The studies had moderate-to-high risk of bias and the evidence was low to very low quality. A supplement may be reasonable when intake is low, but persistent sleep problems deserve proper assessment.
A protein powder mainly helps add protein; a mass gainer typically adds a larger amount of food energy through a mixture of protein, carbohydrate and sometimes fat. Choose according to what is missing from your eating pattern. The largest serving or highest calorie number is not automatically the most useful option.
Protect enough opportunity for sleep, review caffeine and training timing, and seek help when sleep problems persist. A supplement cannot replace a workable sleep schedule or diagnose why you remain tired. One difficult night also does not erase your training progress.
Read labels, compare claims and understand supplement testing in New Zealand.
You do not need a supplement stack to start training. Begin with a repeatable programme, enough food, a realistic sleep routine and a clear reason for any product you add. A useful first purchase solves an identified problem at an acceptable cost; it does not need companions simply because they are sold together.
The safest online purchase is one you can identify, compare and trace after it arrives. A polished website, influencer code or low price does not establish that a formula is right for you. Start with the full label and seller identity, then check the exact serving, total ingredients, delivery and return information, warnings, and any batch evidence that is actually relevant to your use.
No supplement can be treated as risk-free for an athlete who may be drug tested. Contamination, inaccurate labels and prohibited ingredients can create a problem even when the athlete did not intend to take a banned substance. If testing matters, the safest starting point is whether you need the product at all, followed by an exact product-and-batch check with your qualified sport support team.
A supplement sold in New Zealand is not automatically government-approved, independently tested or suitable for every person. Its legal category, ingredients, label and advertising all matter. A useful shopper response is to identify the seller, read the complete label, check the claimed daily serving, and keep medical or medicine questions with a pharmacist or clinician.