Before we get to the FAQ, for those who’ve read my ProLon review and other ProLon related content, and are now looking to purchase a ProLon box, L-Nutra have kindly provided the following ProLon coupon code for FastLifeHacks readers.

USA Readers:

For $25 off each ProLon box, apply the ProLon coupon code: click here to reveal coupon code


UK Readers (USA readers, see above)

For £25 off use the ProLon coupon code: click here to reveal coupon code

For $25 off each ProLon box, apply the ProLon coupon code: TAKE25 - on ProLon’s (newly renovated) website


UK Readers (USA readers, see above)

For £25 off use the ProLon coupon code: FASTHACKSUK




ProLon Frequently Asked Questions

What are the benefits?

Potential benefits include:

  • Decrease in visceral fat (the “bad” fat around the organs)
  • Increase in cellular cleanup (referred to as autophagy) around days 3-5
  • Lowered IGF-1 (due to the reduction in protein intake)
  • Help maintaining healthy blood glucose and healthy blood pressure levels

Other benefits that I personally noticed (n=1):

  • A realisation that I can “survive” with far less food than I’m used to, which was a psychological shift.
  • My skin looked much clearer for about 7-10 days post-fast.

Will I lose weight?

The ProLon diet, specifically a fasting mimicking diet, was conceived with the idea that you could re-create the healthy benefits of fasting without actually eating nothing. Whilst most of the benefits are “below the surface”, things like:

  • Maintain lean body mass
  • Help maintaining healthy levels of systolic blood pressure
  • Increase in cellular cleanup (referred to as autophagy)

ProLon has been shown to help people lose an average of 5.7 lbs. of fat and 1.2 inches off their waist circumference, while preserving lean body mass. These benefits were seen in a clinical trial where participants consumed ProLon once per month, for 3 consecutive months (study source).

One of the most obvious visual differences will be a loss in fat. Excitingly, the weight loss includes the “bad fat” which clumps around internal organs, known as visceral fat. Whilst lean muscle mass gets maintained.

Showing the location of visceral fat, and how it compares to regular fat we think of (subcutaneous)

How big are the meals?

On the first day you’re allowed more food (~1100 calories) than the following four days (~800 calories). Day 1 your food looks like:

And then days 2 to 5 it looks more like this each day:

You’ll notice day 1 has more bars, and doesn’t include the L-drink.

How should I prepare for the fast?

Leading up to your ProLon 5-day fast, you might be thinking, is there anything I should do to get my body ready for this?

There are at least 3 areas to look at:

1) Start Reducing Your Caffeine Intake

On the ProLon diet it’s requested in the instructions that you only consume what’s in the box for each of the 5 days. With at most, if you need it, 1 cup of tea or coffee each day. For heavy coffee drinkers this restriction could come as a shock to the caffeine dependent body. Leading to potential caffeine withdrawal, which can feel uncomfortable, and may manifest itself with a headache, irritability and tiredness.

Cutting down on food is hard enough as it is, so there’s no need to pile on the difficulty.

With this in mind, it makes sense to start cutting down on your caffeine intake in the lead up. Perhaps by switching to de-caffeinated versions of your favourite beverages.

2) Reduce Sugar & Junk Food

Whilst caffeine is without doubt physiologically addictive, sugar can also be addictive, even if it’s predominantly psychological. Because of this, if you current eat a lot of junk, it makes sense to try and reduce it going into the fast.

3) Eat a Healthy Diet Prior

If you’d like some inspiration on your diet leading up to the fast, this meal plan was shared by Dr Felice Gersh (click on it to view a bigger version):

What day is the best day to start?

Now of course you can start the fast on any day of the week you wish. But something that becomes very apparent during the fast is that eating is often as much about fun and excitement, as it is about satiating hunger. And not eating gets very boring very quickly.

Many people decide to start the fast mimicking diet on a Sunday night so they can engage normally in social eating the following weekend. Note that when you finish on the Friday night (last ProLon meal), you don’t resume your normal diet until you wake up on Saturday.

What should I eat after the fast?

For 24 hours following the end of the ProLon, people should follow a diet based on:

  • Soups
  • Complex carbohydrates (vegetables, cereals, pasta, rice, bread, fruit, etc.)

Minimizing consumption of:

  • Fish, meat, saturated fats, pastries, cheeses, milk, etc.
  • Anything too heavy on the stomach

Most people’s reaction (mine included) is to want to feast upon finishing.

Problem is, both your stomach and your gut bacteria have already adapted to the low, restricted foods you’ve been eating, and struggle to handle the big intake of new foods.

This can lead to some uncomfortable stomach ache, and potential trips to the bathroom.

However, if you can manage to take it easy on day 6 with food, you should be in for a smoother ride thereafter.

Which Soup Variety Should I Buy?

Up until August 2019 ProLon had only 1 version of their diet. Since August they’ve introduced “soup variety 2” on when you go to make an order:

How to toggle between the two varieties when ordering

Soup variety 2 swaps out:

  • Mushroom
  • Minestrone with Quinoa
  • Vegetable Soup

And adds in:

  • Butternut Squash
  • Butternut Squash with Quinoa
  • Spinach with White Bean

Below we’ll take a look at how these new soups look, and taste!

Butternut Squash Soup

This soup has a thick texture (owing to the rice flour they added) which makes it feel more substantial as a meal. If you’re familiar with butternut squash – then it tastes just like that – but with a slightly tart (sour) taste to it.

Butternut Squash with Quinoa Soup

This was my favourite of the two butternut squash soups. Whilst I liked the thickness of the “butternut only” version (this one is more watery) I think overall the flavour is slightly nicer.

Spinach with White Bean Soup

In contrast to the sweeter tasting butternut squash soups – this one (unsurprisingly) tastes more of spinach leaves. It’s perhaps a bit bland, but probably quite healthy!

As far as your decision goes, it’ll come down to which soups you like the look of more, and if you have any special dietary needs that one will cater for more than the other. If you’d like to see the new soup’s ingredients list, look here:

Can I Add Herbs & Spices to the Soups?

If you’d like to “spice up” the soups, then the good news is you can. ProLon’s official guidance on this is 1 teaspoon of herbs and spices (maximum) per day. I’ve written a guide here, that provides (tried and tested) recipes for each of the soups. You can follow them to the letter, or you can use them as inspiration for your own recipes.

In that post I’ve included tables with the calorie counts, so you get an idea of how many calories each addition “costs”. I’ve also given a suggestion for balancing the maths on any extra calories you might add.

See ProLon Soup Tips – How to add some flavor and spice to the soups for all the recipes.

How often should I do a ProLon fast?

This is a decision that ideally should be made with input from a doctor or registered dietitian, but broad guidelines are as follows:

Frequency Who it applies to
1x every 6 months For healthy patients with ideal diet who engage in regular physical activity
1x every 4 months For healthy patients with a normal diet who are not physically active
1x every 3 months For average-weight patients with at least one risk factor*
1x every 2 months For average-weight patients with at least two risk factors*
1x month For overweight or obese patients with at least two risk factors*

*Risk factors are in respect to diabetes, cancer, cardiovascular or neurodegenerative disease. Examples of risk factors include pre-existing illness, blood biomarkers, family history and genetic mutations.

How much does ProLon cost?

ProLon costs $249 in the USA ( which includes the cost of shipping. If you order 3 boxes at a time, this is reduced to $225. To get $25 off your purchase, use the ProLon coupon at the top of this page.

For Canadian’s, they order from the same website as USA, so it’s the same price. There then may be an import surcharge on top.

Outside the USA:

ProLon in the UK ( costs £225, or £200 per box if you order 3 boxes. To get £25 off your purchase, use this ProLon coupon at the top of this page.

ProLon in Europe ( generally costs €199, or €185 per box if you order 3 boxes.

Around Europe ProLon ship to:


Hopefully the above helps answer some of the questions you may have, in embarking on your ProLon fast mimicking diet. If you have any questions I didn’t cover, please reach out in the comments.


Posted by John

Researcher & Writer. Interests include Health & Longevity, X-Risk, Renewables, Investing, Decentralized Digital Cash, 90% Dark Chocolate. Tweets at

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