Sorry, you need to enable JavaScript to visit this website.

PKU sphere® is a low phenylalanine (Phe), powdered protein substitute which is based on glycomacropeptide (GMP). When mixed with water PKU sphere is easily made into a drink.

PKU sphere new flavours are here! PKU sphere new Banana and Lemon flavours are ready to be discovered now. Request your samples of PKU sphere by completing our sample form. Your request will be shared with your dietitian for them to approve and then your samples will be sent out for you to try!


What is PKU sphere?

PKU sphere is a low phenylalanine (Phe) powdered protein substitute which is based on glycomacropeptide (GMP for short). When mixed with water PKU sphere is easily made into a drink. The volume can be adjusted to your own preference. PKU sphere is available in two sachet sizes:

  • PKU sphere15 contains the equivalent of 15 grams of protein.
  • PKU sphere15 contains 28mg of Phe.
  • PKU sphere20 contains the equivalent of 20 grams of protein.
  • PKU sphere20 contains 36mg of Phe.
  • PKU sphere also contains a range of vitamins, minerals and DHA (an omega‐3 fatty acid) which are typically found in high protein containing foods such as meat, fish or eggs. These types of foods are restricted in a PKU diet and therefore vitamins and minerals are added to PKU sphere to help meet your daily nutritional requirements.

What makes PKU sphere different to other protein substitutes?

The big difference is that PKU sphere is based on GMP. It contains a blend of both the whole protein GMP and some amino acids, whereas most other protein substitutes are based just on amino acids. You can download the PKU sphere booklet from the useful resources section on this page to learn more about GMP.

Who is PKU sphere for?

PKU sphere is for children and adults with PKU. It is suitable from 4 years of age onwards and can be taken throughout adulthood. PKU sphere, like all GMP‐based protein substitutes contains a small amount of Phenylalanine (Phe), therefore, your dietitian will advise if PKU sphere is suitable for you or your child to try.

PKU sphere is currently being used by lots of people. Vitaflo carried out a short survey to understand more about the experience of PKU sphere users. You can find out more by watching this short video


How much PKU sphere do I need?

The amount of PKU sphere needed will depend on a variety of factors including age and weight. Your dietitian will advise exactly how much PKU sphere will be needed each day.

How do I make PKU sphere?

Making PKU sphere is simple:

For PKU sphere20:

  1. Pour approximately 120ml of water in to a shaker.
  2. Add in one PKU sphere20 sachet.
  3. Shake well and drink immediately.



For PKU sphere15:

  1. Pour approximately 100ml of water in to a shaker.
  2. Add in one PKU sphere15 sachet.
  3. Shake well and drink immediately.



Top tips:

  • Make with ice cold water or lots of ice to get a cool sphere shake.
  • Once made up, drink PKU sphere straight away to enjoy it at it’s very best.
  • The PKU sphere shaker has a separate compartment at the base which holds the contents of one sachet of PKU sphere so it’s even easier to take when you’re out and about.

What flavour is PKU sphere?

PKU sphere is now available in five flavours: 

- Red Berry
- Vanilla
- Chocolate
- Banana
- Lemon

You can choose your favourite PKU sphere flavour to take all the time or you can pick ‘n’ mix the flavours depending on what you feel like each day.

What if I prefer to take a ready‐to‐drink product?

PKU sphere is a powdered protein substitute, which is great if you want the flexibility to make your protein substitute to your own preference. If you prefer a ready‐to‐drink protein substitute click on PKU cooler® and PKU air® on the VitafriendsPKU product journey for more information about Vitaflo’s products.

Sign up to the Vitafriends newsletter and like our Facebook page

Don’t forget to sign up to the Vitafriends newsletter to receive updates about new recipes, our low protein foods and PKU events in your area.

Join the Vitafriends PKU Facebook page to get support from others with PKU.

Other useful bits of information

Please use the 'Useful Resources' section above to view our PKU sphere booklet which includes everything you need to know about GMP and GMP‐based protein substitutes like PKU sphere plus recipes and ideas for shakes and smoothies.

PKU sphere is a food for special medical purpose, and should be used under medical supervision.

Explorers Club

If you haven’t done so already, why not register for the Vitafriends Explorers Club – an education programme for families managing PKU in the early years.

It’s packed full of recipes to help with the introduction of solid foods!