Prolon is the only nutrition program clinically proven to trigger autophagy in humans
Learn moreA clinical protocol. Not a diet
The beer belly isn't about the beer
It's about the kind of weight you lose. Most diets can't tell fat from muscle, and after 40, holding onto muscle gets harder. The Prolon 5-Day Fasting Mimicking Diet (FMD) is formulated to tap into stored fat, including the visceral fat around your organs, while helping protect the lean mass you trained for.
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Studied and validated with
20K+
Physicians
25+
Years of research
41
Clinical trials
130+
Global patents
Head to head · published clinical study
Prolon against the gold-standard Mediterranean diet, over 120 days
Two approaches, one randomized trial. One asked for four months of daily dietary change. The other asked for only five days at a time.
Mediterranean diet
Lost weight. Held the line
- Considered the gold standard for cardiometabolic health
- Delivered cardiometabolic benefits
- Helps maintain muscle mass
- Months of daily dietary change required
Prolon 5-Day FMD
Lost the fat. Kept the muscle
- Matched the Mediterranean diet's cardiometabolic benefits
- Protected more muscle than the Mediterranean diet in the study
- 5.7 lbs off and 1.6 inches off the waist across three cycles
- Five days at a time, not months of restriction
Published clinical results across three consecutive monthly cycles. Individual results vary.
7 reasons it works
Why the belly goes and the muscle stays
Reason 01
What you lose matters more than how much you lose
Cut hard enough and the scale moves. So does your muscle. That's the trade most diets make, and holding onto muscle only gets harder with age. Prolon is formulated to draw on your body's stored fat while helping protect the lean mass you're working to keep. Lighter and softer isn't the outcome you're after.
Published clinical results: 5.7 lbs lost and 1.6 inches off the waist across three consecutive cycles.
Reason 02
Five days, not five months
You are not signing up for a lifestyle change. One cycle is five days; on Day 6 you go back to your normal life - client dinners and travel included. Most users follow three to four cycles a year after an initial consecutive three monthly schedule (only 15 days across 90).
Reason 03
You keep eating
This is not a water fast. Plant-based soups, nut bars, olives, kale crackers and teas, portioned by day and formulated to keep your body in a fasting state while you stay nourished. The box is the whole menu, so there is nothing to plan, count, portion, or decide. You get the benefits of fasting - with food.
Reason 04
The cellular work behind the scenes
Around Day 3, your body activates autophagy, the cellular clean-up process where old, damaged cells are removed or recycled, making way for healthier, younger functioning ones. Prolon is the only nutrition program clinically proven to trigger autophagy in humans.
Reason 05
The other number that moves (biological age)
In published clinical research, three consecutive monthly cycles of the 5-Day program were shown to reduce biological age score by an average of 2.5 years - a figure based on markers in your blood, not the one on your driver's license. It's the number that describes how young or old your body is actually functioning. Users say it also supports energy and mental clarity, which is the part that shows up in a long day, a late flight, or the last hour of a meeting.
Reason 06
No drugs. No injections. No extreme diets
More people than ever are weighing their options: medications that require ongoing use to sustain results, restrictive diets, an ever-growing stack of supplements.
Prolon belongs to a different category. Its five-day protocol is built around fasting biology—using precisely designed nutrition to activate the body’s fasting response while you still eat. You do it for five days, three or four times a year, then go back to your life.
Reason 07
25 years of research from USC, not a wellness trend
The 5-Day FMD was developed by Dr. Valter Longo at the USC Longevity Institute, and touts 25 years of research, 47 clinical trials, 18 research partners including Stanford and Mayo Clinic, 130 global patents, and a network of more than 20,000 physicians. It is the only nutrition program patented for longevity through cellular rejuvenation and proven to trigger autophagy in humans.
Real results
"Life gets hectic, and if I'm losing weight I want to lose the right kind. Prolon's 5-Day is built for that: fat-focused, keeps my muscle, keeps me on track."
Barry Conrad
Prolon partner
Individual results vary. This reflects one customer's own experience with the 5-day protocol and is not a guaranteed outcome.
The 5-day arc
What the body does, day by day
Five days is short enough to plan around, a long enough to reset your body.
Day 1
Transition to fasting. Glucose stores begin to deplete.
Day 2
Stored fat becomes fuel and ketones rise.
Day 3
Autophagy activates. Cellular cleanup begins.
Day 4
Cellular rejuvenation and fat-burning are in full swing.
Day 5
Renewal: cells begin functioning as younger versions of themselves.
Cellular renewal · the bonus round
The part you notice on Monday
The renewal work does not stop at the waistline. Prolon may support energy and mental clarity, and customers regularly report feeling clearer and more confident in the days after a cycle.
User-reported experience. Individual results vary.
Run the protocol
Five days in a box, delivered
Roughly what you would spend on a week of groceries.
One cycle is five days; most users run three to four cycles per year.
Prolon 5-Day FMD
Five days of plant-based soups, bars, snacks and teas. Everything for one cycle, portioned by day.
Your order includes
- The Prolon 5-Day kit: soups, nut bars, snacks and herbal teas
- Free Welcome Kit including a Prolon water bottle, subscribers only
- Free Getting Started Guide, so Day 1 needs no research
- 15 percent off with a subscription, cancel anytime
Choose your flavors
The same science, now in 100 percent organic, pre-cooked soups for taste, ease and convenience.
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Buy 2 boxes
$459.00
Free shipping on orders over $199. Two cycles back to back, or share one with your partner.
One-time purchase
$255.00
One kit, no subscription. Try the protocol once and decide.
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Questions
What men ask before their first cycle
Prolon is formulated to target fat rather than lean mass, with clinical trials showing muscle protection.
For five days, yes. The kit is the whole menu, and alcohol is out because it breaks the fasting state you are paying for. The other 25 days of the month are yours, unchanged. Most men book a cycle into a quieter week, run it Monday to Friday, and are back at the table on Day 6.
Prolon targets visceral fat, the fat stored around your organs rather than the fat you can pinch. Published clinical results across three consecutive monthly cycles: an average of 5.7 lbs lost and 1.6 inches off the waist. Individual results vary.
Prolon 5-Day supports heart health and healthy metabolic markers, and is intended for healthy individuals. If you have medical conditions or are on medication, consult with your healthcare provider before beginning.
Yes. Subscriptions can be paused, skipped, or cancelled at any time, and Prolon is HSA/FSA eligible.
Five days. Real results. Without losing what you built
Lose the fat. Keep the muscle. Run the protocol three times and let the tape measure settle the argument. The program more than 20,000 physicians already work with.
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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.
Clinical results referenced on this page come from published studies of three consecutive monthly cycles of the Prolon 5-Day Fasting Mimicking Diet. Individual results vary. Consult your physician before starting any nutrition program, particularly if you take medication or have a medical condition.
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