Know what is in the tub.
Choose your supplements.

Choosing protein powder and other supplements gets easier once you know what to read on the label. A few facts do most of the sorting: the type of protein, the ingredient list, the flavour, the pack size and the serve size. After that it comes down to cost per serve. This guide goes through each one. We are a store, not doctors, pharmacists or dietitians, so this is a guide to shopping and comparing. It is not health advice.

Start with the type of protein

The ingredient list names the protein source. Most powders use one of four: whey concentrate, whey isolate, casein or a plant protein. Some blend two or more.

Whey concentrate. Whey is the liquid left over when milk is made into cheese. Filtered and dried, it becomes whey protein concentrate. Concentrate keeps some of the lactose and fat from the milk, so it has less protein per 100 g than isolate.

Whey isolate. Isolate is whey that has been filtered further. More of the lactose and fat is taken out, so the powder has more protein per 100 g. It usually costs more per kilo than concentrate. Isolate still comes from milk.

Casein. Casein is the other protein in milk, the part that forms the curd in cheese making. It mixes thicker than whey. On a label you will see it as micellar casein or calcium caseinate.

Mass gainers. A mass gainer is a protein powder with a large amount of added carbohydrate. Serves are much bigger than for a plain protein powder, often 100 g or more, so a tub holds fewer of them. Check the serve count before you compare prices.

Plant protein. Plant powders are made from pea, rice, soy, hemp or a blend of these. They contain no milk ingredients, but still read the allergen statement, because soy is an allergen and some products are packed on shared lines. Plant powders tend to taste earthier and feel grainier than whey.

Read the ingredient list

Ingredients are listed by weight, heaviest first, so the first few make up most of the product. In a protein powder, the protein source should come first.

After that you will usually see flavouring, a sweetener, a thickener and sometimes an emulsifier such as lecithin, which helps the powder mix. Sweeteners are named, so you can see whether a product uses sugar, stevia, sucralose or something else.

Blends. Some labels list a blend under one name with the parts in brackets. The parts are still in order by weight, but the label may not say how much of each there is.

Single-ingredient products. Plain creatine monohydrate and unflavoured protein often have one ingredient. That makes them the easiest products to compare. The ingredient is the same, so look at the pack size and the price.

Check the allergen statement

Food labels in Ireland declare common allergens such as milk, soy, egg, peanuts, tree nuts, wheat and gluten. Look for them in bold in the ingredient list and again in the line that starts with "Contains".

Whey and casein are milk. Protein bars often contain nuts, soy or wheat. Many labels also carry a "may contain" line for products made on shared equipment.

Read the ingredient list on the product page, then read the label again when the pack arrives, because makers change recipes. The label on the pack you receive is the final word. If you have a food allergy, ask your doctor before you try a new product.

Flavoured or unflavoured

The same powder is often sold in several flavours. Chocolate and vanilla are the common ones, and they are the easiest to mix with other things.

Flavoured powders contain flavouring and usually a sweetener. Unflavoured powders leave both out, so the ingredient list is shorter. They taste plain, and most people mix them into something else.

If you are trying a flavour for the first time, buy the smallest pack. Change-of-mind returns only apply to unopened packs, so you cannot send a tub back because you did not like the taste.

Pick a pack size

Powders come in sizes from single-serve sachets to tubs and bags of several kilos. Small packs cost more per serve and suit a product you have not tried. Large packs cost less per serve and suit a product you already know.

Tubs are easy to scoop from and reseal. Pouches and bags take up less room in the cupboard, but check the zip is fully closed after each use.

Weight is only half the story. Two 1 kg packs can hold a different number of serves, because one uses a 25 g serve and the other a 40 g serve. Compare the serve count as well as the weight.

Work out the cost per serve

Pack prices are hard to compare because packs come in different sizes, and serve sizes differ too. Two sums fix that.

Cost per serve. Divide the price by the number of serves. A 1 kg pack with a 30 g serve holds about 33 serves. At €35, that is about €1.05 a serve.

Cost per 100 g. Divide the price by the pack weight in grams, then multiply by 100. That €35 pack costs €3.50 per 100 g. A 2 kg pack at €60 costs €3 per 100 g. Bigger packs usually cost less per 100 g, but only buy a size you will finish before the best before date.

Use cost per 100 g when two products have different serve sizes. A product with a small serve can look cheap per serve and still cost more by weight.

Bars and ready-made shakes. These are sold by the box or multipack. Divide the price by the number of bars or bottles to get the cost of each one.

Powder, capsule, bar or ready-made

Many ingredients are sold in more than one form. Powder is usually the lowest cost per serve, and you mix it yourself. Capsules and tablets need no mixing and have no taste, and the label says how many make one serve.

Bars and ready-made shakes need no preparation and usually cost the most per serve. Bars have longer ingredient lists than powders, so read them with care, starting with the allergen statement.

Creatine, amino acids, electrolytes and the rest

Creatine. Most creatine is sold as creatine monohydrate, a plain white powder with no flavour. Serves are small, usually a few grams, so a 500 g pack holds a lot of them. Some products are flavoured or come as capsules, and the label says which.

Amino acids. These are mostly flavoured powders that you mix with water. The label lists which amino acids are in the product and how much of each is in a serve.

Electrolytes. Electrolyte products come as powders, sachets or tablets that dissolve in water. The label lists the minerals in each serve, such as sodium, potassium and magnesium, and how much water to use.

Collagen. Collagen is a protein powder made from animal sources, most often beef or fish. The label names the source, which matters if you avoid one or the other.

Greens and fibre. These powders are blends of dried, ground plants and plant fibres. Their ingredient lists can be long. Read them in full, and check the serve size, because it varies a lot between products.

Caffeine and who should avoid sports foods

Some products contain caffeine, mainly in the pre workout category. Look for caffeine in the ingredient list. It can also come from ingredients such as guarana, green tea extract or coffee.

Read the directions and warnings on the label and stay within the stated serve. If you want no caffeine at all, check the ingredient list on the product page before you order.

Sports foods are made for adults. They are not suitable for children under 15 or during pregnancy. If you have a health condition or take medication, ask a doctor or pharmacist before use. We are a store and cannot advise on any of that.

Mixing and directions

Directions come from the maker's label and are on each product page. They give the serve size and how much water or milk to mix it with.

Use the scoop that comes in the pack, because scoops differ from product to product. For a closer measure, weigh a serve on kitchen scales. In a shaker bottle, add the liquid first and the powder second, which helps stop lumps sticking to the bottom.

Follow the label and do not go over the daily amount it states.

Storage and best before dates

Keep powders in a cool, dry place, out of the sun, with the lid on tight or the pouch sealed. Moisture makes powder clump, so use a dry scoop and keep the tub away from the kettle and the stove.

Every pack carries a best before date and a batch code. Check the date when your order arrives. If you buy a big pack, divide the number of serves by how many you use in a week to see whether you will finish it in time.

Keep bars and ready-made shakes out of the heat. A hot car will melt a coated bar.

Your supplement buying checklist

Pick the category. Read the ingredient list and find the protein source or main ingredient. Check the allergen statement. Choose a flavour, or go unflavoured. Note the pack size and the serve size, and work out the cost per serve. Check for caffeine. Pick a pack you will finish before the best before date. Then check the order total, in euro: delivery is free at €55 or more.

The short version

Read the ingredient list and the directions instead of the front of the tub, and compare on cost per serve or per 100 g. Every product page here lists the pack size, flavour, ingredients and directions so you can decide before you order. If you change your mind, you have 14 days from delivery to return packs that are still unopened and sealed.