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ProLon L-Drink Glycerine Content – DIY Version

The fast mimicking diet is low in a number of things, including total calories and protein. Valter notes in the below video that it’s not just what the diet lacks, it’s also about what the diet contains, that gives it the positive results.

The ProLon box contains a 118ml (4 fl oz) bottle of liquid, called L-Drink, for each of days 2 to 5. Based on your body weight, you decant a specified amount of the L-Drink into a water bottle, and dilute the rest with tap water. Then you aim to drink the whole thing throughout the day.

ProLon L-Drink – interestingly the orange flavour is cloudy and the lemon is clear – presumably due to the contents of the flavoring used

L-Drink Function

Valter describes the function of the L-Drink as being to provide an external source of glycerol. People who are in a fasted state naturally produce glycerol, and this is used for gluconeogenesis (the production of glucose (energy) from non-carbohydrate substrates like fat and muscle). Valter notes in the video below that after 3 ProLon cycles, when measured, people are found to have lost minimal amounts of muscle – and one of the reasons could be due to the L-Drink.

L-Drink Ingredients & Functions

  • Purified water: Unlikely to form any function, other than as a base to mix the rest of the ingredients into, and then bulk them up for measuring out quantities
  • Vegetable glycerine: As mentioned above, this provides the body with an external source of glycerol to aid in gluconeogenesis
  • Natural flavor: To make more interesting to drink, and perhaps mask any uncomfortable taste from the glycerine
  • Potassium sorbate: Whilst potassium is an electrolyte, it doesn’t seem common to choose it in sorbate form for electrolyte purposes. Therefore it’s most likely that potassium sorbate is included for preservative reasons – to extend the shelf life of L-Drink

How Much Glycerine to Use?

Whilst the L-Drink nor its labels say the exact amount (in grams) of glycerine they’re using, we can still use inference to calculate it with reasonable precision. I’ve turned this calculation into a calculator, which you can use below:

[sc name=”accordian-code” ][/sc] [sc name=”glycerine-calculator” ][/sc] [sc name=”accordian-glycerol-calculations” ][/sc]

Once you have calculated how much vegetable glycerine you would need per day, you can then:

  • Measure this out each day on days 2, 3, 4 & 5.
  • Add it to a water flask, and shake to mix. If it’s not mixing due to the water being cold, using warmer water may help with initial mix.
  • Optionally add a calorie free flavouring. The L-Drink does this to improve palatability.

Is Vegetable Glycerine Safe?

Vegetable glycerine is commonly used in food & cosmetics. For example in food, it’s used to prevent icing setting too firm, and for making ice cream softer to scoop.

In a 2012 study into the effectiveness of glycerol for sports performance, they used a dose of 1.2 grams per kilogram of bodyweight for each study participant, with no noted adverse health effects1The Effect of Glycerol Supplements on Aerobic and Anaerobic Performance of Athletes and Sedentary Subjects – J Hum Kinet | 2012.

1.2g/kg is a much higher dose than is used in ProLon.

For clarity – glycerine and glycerol are the same thing, however commercially it’s often referred to as glycerine, and inside the body as glycerol.

Where can I buy vegetable glycerine?

Many will be familiar with seeing glycerine available in supermarkets, typically in the baking aisle. It can also be found on Amazon and other online retailers. You can check if it is “food grade” just to be on the safe side.


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10 months ago

I really appreciate your effort. Maths are not my strong suit. Thank you so much!

7 months ago

Thanks. I’m on my 2nd round of the Prolon fast. I had great success with the first round. I’ve adopted it for general health, not just for weight loss. However, I dropped a few pounds and have kept them off. I was most surprised to see that my athletic strength didn’t suffer at all. I was expecting to lose muscle mass. In fact, by Day 4 of the fast, I was cycling as strong as I had been the week earlier: 20 miles and 2,000 feet of elevation, in spite of the low calorie diet. The glycerine might have played a big role. I was probably burning fat more than I do normally. Thanks for the explanation.