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Stubborn weight after 45 isn't a willpower problem.7 reasons the Prolon 5-Day works on the biology instead.
If eating less and moving more stopped moving the scale, you're not imagining it, and you're not doing anything wrong. The Prolon 5-Day Fasting Mimicking Diet is a five-day precision nutrition program clinically formulated to help you lose fat while protecting the muscle that supports a strong metabolism.
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★★★★★
4.4 program rating
47 clinical trials
1M+ happy customers
USC Longevity Institute
· Stanford · Mayo Clinic
20,000
healthcare professionals
25+
years of research
200+
patents
You didn't need more discipline. You needed a different method.
The Prolon 5-Day FMD
Works on the biology
Targets fat, not muscle
Average 5 lb fat-focused weight loss per cycle, user-reported
Five days at a time, three to four cycles a year
You eat real food the whole time
Eat-less, move-more dieting
Runs on willpower
The scale can't tell fat loss from muscle loss
Depends on daily discipline for months at a stretch
Results often fade when the restriction ends
Long stretches of food deprivation
Based on Prolon's clinical research. Individual results vary.
Why it works
7 reasons the weight comes off, and stays off
When paired with balanced eating and a healthy lifestyle between cycles.
1
It was never a willpower problem
You did the things that used to work. Smaller portions, more steps, fewer carbs. The effort was there. The results weren't. That experience is common after 45, because the body changes what it does with food and muscle over time, and a method built on eating less and pushing harder can stop matching the body it's aimed at.
The answer isn't more restriction. It's a method that works on what changed.
2
Lose the fat. Keep the muscle.
Muscle matters more after 45, because it's part of what supports a strong metabolism - and it becomes harder to keep. Most diets can't tell the difference between fat and muscle; they just drop the number on the scale. The Prolon 5-Day is clinically formulated to target fat while protecting muscle. In one study, it was shown to protect more muscle than the Mediterranean diet.
In clinical research, participants saw an average of 5.7 lbs and 1.6 in. off the waist over 3 cycles, with muscle protected.
Average 5 lb fat-focused weight loss per cycle, user-reported · Individual results vary
3
It's resetting metabolism from the inside out
The Prolon 5-Day isn't another restriction plan. It's precision nutrition: plant-based soups, nut bars, olives, kale crackers, and herbal teas, formulated to keep your body in a fasting state while you eat. Your body shifts to stored fat for fuel, and real changes begin inside.
Reset the body, from the inside out. No counting, no weighing, no guessing. Everything for all five days comes in the box.
4
The cellular cleanup most plans never touch
By Day 3, your cells enter autophagy, the body's cellular cleanup: damaged cellular components clear out. Then renewal follows, making way for healthier, younger functioning cells. Cutting calories alone doesn't reliably get you there; it usually takes 72 hours of water fasting to get there. But Prolon has been clinically proven to trigger it - with food.
This is the deeper work that eating less on its own was never doing.
The only nutrition program clinically proven to trigger autophagy in humans
5
Cells that function as younger versions of themselves
The fat is only part of the story. The Prolon 5-Day can help your cells function as younger versions of themselves, and in clinical research it was shown to reduce biological age by up to 2.5 years after three consecutive monthly cycles.
At 45 and beyond, that matters as much as the scale.
Reduced biological age by up to 2.5 years after three consecutive monthly cycles · Individual results vary
6
No drugs. No injections. No months of restriction.
Five days, then back to eating the way you normally eat. No prescriptions, no needles, no long-term food deprivation. Most users follow three to four cycles yearly, with the benefits compounding over time.
Honestly: some people do feel hungry at points, especially on the first cycle, and that's normal. It tends to get easier with each cycle, and staying hydrated really helps!
7
25+ years of research, not a wellness trend
The Prolon 5-Day FMD is grounded in the research of Dr. Valter Longo at the USC Longevity Institute: 25+ years of clinical research, 47 clinical trials, 18 leading research institutions including USC Longevity Institute, Stanford, and Mayo Clinic, 200+ patents, and recommended by 20,000 healthcare professionals.
It's the only nutrition program patented to support longevity through cellular rejuvenation.
★★★★★
"I experience great sustained energy, better-looking skin, better sleep, and a sense of achievement every time I complete the five days. As a scientist myself, the work and science behind the program drove me to try it."
Liz
Verified Prolon customer
User-reported experience. Individual results vary.
Real customers, in their own words
Real Prolon customers. Individual results vary.
How the body shifts, day by day
Day 1
Body adjusts to lower glucose
Day 2
Stored fat starts mobilizing, ketones rise
Day 3
Autophagy activates, cellular cleanup begins
Day 4
Autophagy and fat-burning are in full swing
Day 5
Cells renew, functioning as younger versions of themselves
Cellular renewal can continue into Days 6 and 7.
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★★★★★
4.4 program rating · 1M+ happy customers
Prolon 5-Day Fasting Mimicking Diet
A five-day precision nutrition program clinically formulated to target fat, protect muscle, and reset the body, from the inside out.
Targets fat, not muscle
The only nutrition program clinically proven to trigger autophagy in humans
No drugs, no injections, no long-term food deprivation
Plant-based: soups, nut bars, olives, kale crackers, herbal teas
HSA/FSA eligible
Subscribe & Save 15%
HSA/FSA
eligible
90-day
money-back guarantee
1M+
happy customers
Most customers run three to four cycles per year. Individual results vary.
What's in the box
What people ask before their first Prolon cycle
I've tried everything. How is this different?
Most approaches to weight after 45 rely on sustained restriction: eat less, for longer, with more discipline. The Prolon 5-Day works differently. It's precision nutrition that keeps your body in a fasting state while you eat, so your body shifts to stored fat for fuel and enters autophagy, the cellular cleanup that calorie-cutting alone may not trigger. It runs five days at a time instead of asking for months of willpower.
How much weight will I lose?
Individual results vary. Users report losing an average of 5 lbs of fat-focused weight per cycle. In clinical research, participants saw an average of 5.7 lbs and 1.6 inches off the waist over 3 cycles, with muscle protected.
Will I be hungry?
You eat every day of the program: plant-based soups, nut bars, olives, kale crackers, and herbal teas, formulated to keep your body in a fasting state while you stay nourished. Some people may feel hungry at some points, especially during their first cycle (users report it gets easier with each round), and that's normal - but staying hydrated helps!
Will the weight stay off?
In clinical research, the majority of the weight loss stayed off even after participants returned to normal eating. Combined with balanced eating and a healthy lifestyle between cycles, the 5-Day Program shows support for sustained results. Most users follow three to four cycles yearly, with the benefits compounding over time. Individual results vary.
Is it safe for me?
The Prolon 5-Day is a food-based nutrition program, not a medication. It's backed by 47 clinical trials and recommended by 20,000 healthcare professionals. It is intended for use by healthy individuals who want to support their health and wellbeing, and by overweight individuals who want to proactively manage their weight in a healthy way. If you are on medication or have a pre-existing medical condition, consult your healthcare provider before beginning.
Work with your biology, not against it.
Lose the fat. Keep the muscle. Reset the body, from the inside out. Five days at a time, three to four times a year.
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© Prolon · L-Nutra. Patented fasting mimicking technology developed with the USC Longevity Institute.
These statements have not been evaluated by the FDA. Not intended to diagnose, treat, cure, or prevent any disease. Individual results vary.
Prolon 5-Day Program · $225 $191.25