IO Genix Casein - Fonterra Slow-Release Micellar Casein

What is IO Genix Casein?

IO Genix Casein is a powdered micellar casein, providing 23 g of protein per 30 g serving. The raw material comes from New Zealand's Fonterra, one of the largest dairy processors in the world. The 900 g tub holds 30 servings, which is a month at one serving a day.

Micellar casein is not a slowed-down whey: it is the other milk protein, the one that makes up roughly 80 % of milk's protein fraction. What sets it apart is physical rather than chemical. On contact with stomach acid it forms a gel that empties slowly, which spreads the release of amino acids over several hours, where a whey is absorbed in an hour and a half. That is exactly what you want for the long overnight gap.

The flavours listed are Intense Chocolate and Original Black Cookies. The rest of the Spanish range appears in our IO Genix aisle.

What does a 30 g serving contain?

The per-100 g values are calculated from the manufacturer's declaration for a 30 g serving. Two caveats deserve to be set out in black and white.

First, the manufacturer does not publish the energy value of its product in the information available to us. We will not invent it; the label on the tub you receive is required to carry it.

Second, the published amino acid profile is arithmetically impossible: it states 20.1 g of BCAAs and 20.4 g of glutamine "per serving", which would make 40.5 g of amino acids in a serving that contains only 23 g in total. Those values are most likely expressed per 100 g of protein, but we will not decide that on the manufacturer's behalf and we would rather reproduce none of these figures than publish false ones. It is a point we have raised with them.

23 g of protein for 30 g of powder works out at 76.7 % — a very good rate for a casein, most of them sitting between 70 and 78 %. The manufacturer for its part states 75 %: the gap is minor and comes from rounding, but we would rather flag it than ignore it.

The figure worth pausing on is the 450 mg of calcium per serving, or 56 % of the daily reference value. This is not an addition: casein naturally carries milk's calcium, in the form of phosphate bound to the micelles. An evening serving therefore covers more than half of the daily calcium requirement, and calcium contributes to normal muscle function and to the maintenance of normal bones. It is the only genuinely quantifiable nutritional argument on this page, and it is a sound one.

The 1.5 g of carbohydrate and 0.8 g of fat per serving are low, which leaves a very clean shake, somewhere around a hundred kilocalories. That is consistent with the main use: an evening serving, when you no longer want to add anything to the day.

Lastly, the formula contains DigeZyme®, a complex of five enzymes — amylase, protease, lactase, lipase and cellulase — whose quantity is not published. The theoretical benefit is digestion of the powder, and lactase in particular for the residual lactose fraction. We cannot say more than that without a dose, and no claim is authorised for this complex. If digestion is your main problem, our digestive enzymes aisle offers products dosed for exactly that.

Ingredient list

Fonterra micellar casein (MILK), magnesium citrate, L-glutamine, cocoa powder, flavourings, emulsifier (SOYA lecithin), L-arginine HCl, L-ornithine HCl, L-lysine HCl, sweeteners (sucralose and sodium saccharin), DigeZyme® (multi-enzyme complex based on amylase, protease, lactase, lipase and cellulase) and vitamin B6 (pyridoxine hydrochloride). Contains MILK and SOYA lecithin. Possible traces of GLUTEN (OATS), EGG, FISH, NUTS and PEANUTS.

How do you take IO Genix Casein?

Serving: 30 g, that is one of the included scoops. Liquid: 200 to 250 ml of water or skimmed milk. Timing: 45 minutes before bed, or between two widely spaced meals. Frequency: one serving a day. Duration: no course duration, use is ongoing.

A shaker will do, but a blender gives a far better result: casein is thicker than a whey and lumps easily if you pour the powder in before the liquid. The order matters — liquid first, powder second.

Do not use hot water. Heat denatures the protein and turns the shake into something grainy and unpleasant. It is the number one cause of disappointment with a casein, and it is settled in one sentence.

A tip we hand out systematically across the counter: with only 100 ml of liquid and a spell in the fridge, the same serving takes on the texture of a dessert cream you eat with a spoon. For an evening serving that changes everything: it becomes a dessert rather than a shake, and it solves the problem for those who have no wish to drink half a litre before going to bed.

Casein combines without difficulty with a whey isolate taken at another point in the day: one after training, the other in the evening. That is not redundancy, it is two different speeds for two different needs.

Who is this casein right for, and who is it not right for?

It suits someone who eats dinner early and goes to bed late, someone who struggles to hit their protein target across the day, and someone looking for a filling serving at the end of the day. It also suits a calorie deficit, because a thick shake sits in the stomach far longer than a whey.

It contains milk and soya lecithin, which rules it out for anyone allergic to either of those two ingredients. Traces of gluten, egg, fish, nuts and peanuts are also flagged. It is not recommended for children, or for women who are pregnant or breastfeeding.

It is not suitable for the most sensitive lactose-intolerant users. Micellar casein contains little of it, and the presence of lactase in the DigeZyme® complex helps, but "little" is not "none at all". With a marked intolerance, a plant protein or a heavily filtered isolate remains safer.

What you should not expect from it: it does not build muscle overnight, and the idea that casein "protects against night-time catabolism" is a marketing line more than a demonstrated result. What it actually does is add 23 g of quality protein to a day that is short of it, at a moment when you are no longer hungry. That is concrete, it is useful, and it is enough to justify the purchase — but if your daily protein intake is already met, the additional benefit is slight.

Casein or whey for the evening serving?

It is the most common question in the protein aisle, and the answer is not the same for everyone.

A whey is absorbed quickly, with a peak of amino acids within the hour. It is the better choice after training, or when you want a light shake that does not sit heavily on the stomach. In the evening, its weakness is mechanical: the peak falls away within two hours, and there are seven hours of night left behind it.

Casein does the opposite. It rises less high, but it holds for several hours, and it is far more filling. It is the better choice for the bedtime serving, for a day with a long gap between two meals, or for someone who gets hungry in the evening and wants to avoid snacking. Its weakness is the texture: thicker, heavier, and noticeably less pleasant than whey for anyone who does not care for it.

If you are only going to buy one tub, buy an all-round protein. Casein is a second-line product: it makes sense once the first is already in place and you are looking to cover a specific slot.

Frequently asked questions

How many servings in a 900 g tub?

Thirty, at 30 g per serving, which is a month at one serving a day. It is a size consistent with the product's main use: an evening serving, every evening. If you only use it on training days, the tub will obviously last longer.

Can it be mixed with milk?

Yes, and it markedly improves both the taste and the texture. Skimmed milk adds about 5 g of protein and around ten grams of carbohydrate per 250 ml, which remains reasonable in the evening. With water, the shake is lighter and lower in calories, but also blander.

Why should you not use hot water?

Because heat denatures the proteins and makes the casein coagulate, so it turns grainy and unpleasant in the mouth. The nutritional content is not destroyed for all that, but the shake becomes hard to finish. Cold or room-temperature water only.

How do you get a dessert-cream texture?

Use only 100 ml of liquid instead of 250, mix thoroughly, then leave it in the fridge for thirty minutes. The casein swells and takes on a pudding-like consistency you eat with a spoon. It is the best use of the product for those who dislike drinking before sleep.

Is casein suitable for lactose-intolerant users?

Partly. It contains far less of it than a whey concentrate, and the lactase in the DigeZyme® complex breaks down part of what remains. That is enough for most moderate intolerances, but not for the more marked ones. If in doubt, start with a half serving.

Can it be taken after training?

Nothing forbids it, but that is not its territory. After a session, a fast-absorbing protein fits the moment better. Keep casein for the evening or for long gaps: that is where it brings something a whey cannot.

Why is there magnesium citrate in the list?

It appears second in the ingredients, which suggests a not insignificant quantity, but the manufacturer does not publish the dose. We therefore cannot state anything about its contribution or make any claim. If magnesium is what you are after, a dedicated product with a stated dose remains the right choice.

Where to buy IO Genix Casein?

The flavours can be ordered from this page, and we ship throughout France and Europe. At the Vendargues shop, about ten minutes from Montpellier, this is the product we recommend to those who tell us they get hungry at 10 pm: a casein prepared with a thick texture solves that problem better than any appetite suppressant. The rest of the protein aisle can be browsed in our sports nutrition range.