The Prolon 5-Day FMD kit contains five small boxes, each labeled for one of the five days of the program. Each day's box contains all the food, beverages, and supplements you'll consume for that specific day—you’ll see all the items laid out in the meal card included in the kit. We’ve made suggestions as to which items you may consume for breakfast, lunch, dinner, and snacks, but the order in which you consume each day’s items is up to you. However, don’t switch items from one day to another, as each day’s plan is precisely calibrated to activate different phases of cellular renewal.

When you do a cycle of Prolon, something remarkable happens in your body— autophagy. Autophagy is the body's natural cellular cleansing and repair process. During this state, the body breaks down and recycles damaged components to enhance efficiency, generate energy, and support new cell growth. Recognized for its role in slowing aging, reducing inflammation, and protecting against diseases like cancer and neurodegeneration, autophagy was the subject of the 2016 Nobel Prize for Physiology or Medicine. Autophagy is typically activated after 72 hours of nutrient deprivation; the Prolon program was designed to activate autophagy by providing scientifically developed foods that stay below the body's nutrient-sensing pathways, allowing it to maintain a fasting state. Once autophagy clears out cellular debris, the body makes way for younger, higher-functioning cells. These vibrant cells help improve efficiency, support healthy metabolic markers, and slow the aging process—a transformation known as cellular reprogramming.

Prolon provides the body with a scientifically developed, naturally occurring combination of macronutrients (fats, carbohydrates, proteins) and micronutrients (essential vitamins and minerals) designed to keep the body nourished while giving it the benefits of fasting. Each day of the Fasting Mimicking Program is structured to activate different phases of cellular renewal.

Here’s what’s happening inside:

Day 1: Transition to a fasting state Today, your body starts adapting to reduced calorie intake, depleting glucose stores (your primary energy source) and paving the way for fat-burning and cellular benefits. As your body shifts into fasting mode, you might notice cravings or fatigue, but these sensations are short-lived as your system adapts.

Day 2: Ketosis For most, fat-burning is in full effect! By now, your glucose stores are depleted, and your body is fully transitioning to burning fat for energy, or ketosis. Unlike traditional fasts that can lead to muscle loss, Prolon is designed to protect lean muscle while supporting fat burning. As the adjustment continues, you may experience temporary symptoms like brain fog, headaches, or fatigue. Some gastrointestinal discomfort is also normal due to Prolon’s high fiber content. These are all signs of your body adapting—and they’ll soon pass!

Day 3: Autophagy By now, something incredible is happening—your body is transitioning to autophagy, the natural process that eliminates and recycles old, damaged cells. This powerful repair mechanism helps pave the way for cellular renewal, fostering more efficient cells that support healthy aging (both inside and out!) Today might feel more challenging, but remember that any symptoms you experience are signs of deep cellular transformation at work.

Day 4: Cellular rejuvenation Your body is now in a heightened state of cellular rejuvenation, with autophagy in full swing, actively repairing and renewing cells. Fat burning is also at its peak, providing a steady, efficient energy source. These powerful processes are working together to revitalize your body, and their benefits will continue to build—even beyond the completion of the program. Some participants experience "keto-euphoria" at this stage, an increase in mental clarity, focus, energy, and vitality. Hunger often diminishes, making the fast feel easier.

Day 5: Deep renewal and change Your body has undergone a significant transformation: Autophagy recycled and removed old cells to replace them with younger, high-functioning components. These cells now function as younger versions of themselves, supporting lasting benefits. On Day 5, you may wake up feeling sharper, recharged, and lighter, with a renewed sense of energy and a change on the scale—a testament to all the amazing work your body has done.

What’s next? Even though your 5-day program is complete, the benefits of autophagy continue well into Day 7! Day 6 is your transition day, and we suggest beginning with small, light, or liquid meals introducing foods back in slowly: for breakfast, try an L-Protein smoothie, toast with L-Spread, or buckwheat porridge. Lunch might include a veggie bowl with beans and avocado, while dinner could feature salmon, rice, and broccoli. By Day 7, you can gradually return to your normal diet. To maintain Prolon’s benefits and support your healthy aging, we recommend following the principles outlined in The Longevity Diet. Based on the eating patterns of those in areas with the largest concentration of people living healthily into their hundreds, it focuses on primarily plant-based eating with balanced amounts of protein.

While the purpose of the Prolon program is to trigger rejuvenation, weight loss can be another benefit for those who are looking to manage their weight. Everyone is different, and weight loss depends on a number of factors. The average weight loss for program users is about five pounds after one cycle. And the program has been shown to reduce waist circumference by 1.5 inches after three cycles. What’s most important is the kind of weight loss you experience doing the program. The FMD is proven to target visceral fat while protecting muscle. This is in contrast to extreme diets and weight loss drugs that result in substantial muscle loss along with weight loss. And with Prolon, weight loss is sustained even after returning to normal diet

While there are many different signaling factors in the “nutrient-sensing pathways” involved with cellular fasting, the three primary nutrient-sensing pathways that Prolon and fasting down-regulate are IGF-1, mTOR, and PKA. The process is complex, and each pathway can interact with other pathways, but in general, PKA responds primarily to sugar and carbohydrates, while IGF-1 is primarily responsive to protein (and more strongly triggered by animal protein), and mTOR is triggered by IGF-1 and amino acids. Sugar and carbohydrates (and to some extent caffeine) will activate PKA. These nutrient-sensing pathways all help regulate the cells’ growth cycles and stress-resistant “fasting” state.

Day 1 has about 1100 calories (kcals), while Days 2-5 have between 700 and 800 calories (kcals) per day.

Prolon is intended for use by healthy individuals who want to enhance their health and wellbeing, and by overweight individuals who want to proactively manage their weight in an easy and healthy way. Prolon has been shown to help maintain healthy levels of systolic blood pressure while reducing abdominal fat and waist circumference*.

Do not fast or use a fasting product to support fasting if:

• You have a known, diagnosed, or suspected eating disorder
• You have a fever, cough, diarrhea, signs of an active infection, are at risk for recurrent infection
• If your BMI is under 18.5
• You are breastfeeding or are pregnant
• You have dietary restrictions
• Are under the age of 18 or over the age of 70
• If you have experienced protein deficiency or are malnourished

Additional information can be found here.