Lose weight.
Don't lose muscle.

The medication brings your weight down. But which weight? Without a method, a significant part can be lean mass. With the right protein, strength training and the principles of the Longevity Diet, you protect what you want to keep.

Discover the program
Is the program right for me? Take the test
  • Protein at every meal
  • Small portions, easy to tolerate
  • Strength training included
  • Body composition monitoring
  • Mostly plant-based protein
  • Nutritionist coaching every month

GLP-1-RA without a method vs. with a method

Same goal, two very different paths.
The method: protein supplementation, strength training and the Longevity Diet.

GLP-1-RA without a method
Recommended With protein + Longevity Diet
Protein needs
No target: with less appetite you eat less of everything, protein included
A target calculated on weight, age and type of diet, and personalized by the professional
Protein quality
Random: whatever you manage to eat
Mostly plant sources, complete in essential amino acids
Protein distribution
Skipped or irregular meals
Protein at every meal, within a window of about 12 hours
Meal volume
Large meals that are hard to tolerate with nausea and fullness
Small, concentrated portions: a shake or a bar
Strength training
Not included
An integral part of the program
Diet quality
You eat less, but not necessarily better
Legumes, vegetables, whole grains, extra virgin olive oil, fish
Monitoring
Only the weight on the scale
Body composition, strength and habits
After therapy
No habits built: risk of regaining weight
An eating pattern to keep over time

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What the studies say

Without a method

Up to 40% of the weight lost can be lean mass

In the STEP 1 DXA substudy, nearly 4 in 10 kg lost were lean mass. Across placebo-controlled trials, the average is around 3 in 10.

About ⅔ of the weight lost regained after stopping

In the STEP 1 extension, one year after stopping semaglutide, participants had regained on average about two thirds of the weight they had lost.

Less hunger also means less protein

Reduced appetite and gastrointestinal issues make it harder to reach your protein needs from meals alone.

Sources:

1.⁠ ⁠Wilding JPH et al. N Engl J Med 2021 (Suppl. Appendix, Table S5); 
2.⁠ ⁠Beavers KM et al. Obesity 2025.
3.⁠ ⁠Wilding JPH et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab. 2022.
4.⁠ ⁠Mozaffarian D et al. Am J Clin Nutr 2025

Pouring an L-Protein shake from a blender, next to the L-Protein pouch

Four pillars to protect lean mass

With a method

01

The right amount

A protein target calculated for you and checked with the professional who follows you. Protein contributes to the maintenance of muscle mass.

02

The right source

Mostly plant-based protein, made complete by the addition of L-methionine.

03

The right timing

Protein spread across every meal and around training, in small portions that are easy to tolerate.

04

Muscle at work

Regular strength training: without that stimulus, protein alone isn't enough to preserve muscle.

L-Protein Bar held up in one hand

Lots of protein, little volume.

With a GLP-1-RA, a large meal can become an obstacle. Prolon products from the Protein range let you add quality plant protein without feeling weighed down.

Is your protein protecting your muscle?

Take the test

Important notes: Prolon products do not replace or interact with drug therapy: do not change or stop your treatment without your doctor's advice. Food supplements should not be used as a substitute for a varied and balanced diet. If you have kidney disease, consult your doctor before increasing your protein intake.

Free 2-minute test

Is your protein working for your longevity?

Ten quick questions on how much protein you eat, where it comes from and when. Find out whether your habits are helping you age well – and what to change first.

This test is for information only and is not medical advice.

Longevity Protein Program

Who it's for

For anyone who wants to reach the right protein intake following the principles of the Longevity Diet, with plant sources and without excess.

Find out if the program is right for you

What's included

Every month you'll receive:

  • 1 box of L-Protein Bar12 bars
  • 1 box of L-Protein Shake12 shakes
  • 2 L-SpreadAlmond and cocoa spread
Plus, every month: a 30-minute coaching session with a nutritionist

Together you'll define your protein needs, the best moment for each product and how to fit them into your diet.

€119/month
Start the program
  • The subscription renews automatically every month and can be stopped at any time from your personal area.
  • The Smart Scale offer is only valid with advance payment for 3 months of the program.
  • The products should not be consumed during fasting hours or during the 5 Prolon days.