Prolon focuses on structured fasting programs designed to support metabolic and cellular health. It positions its approach as a guided nutrition protocol built around timing, portion control, and specific nutrient composition.
The brand claims that its primary offering is designed to activate fasting-related processes linked to metabolic reset, cellular renewal, and improved insulin response. It may help reduce some of the physical and adherence challenges commonly associated with traditional fasting methods.
In this review, we will take a closer look at Prolon’s product offerings, the brand’s core approach, and potential advantages, as well as its limitations and areas of concern. We will also examine consumer feedback and overall brand positioning to provide a balanced perspective on whether Prolon’s structured fasting model aligns with different fitness goals and user expectations.
About Prolon
As per the official website, Prolon is based on long-term research into aging, metabolic function, and nutrition-based interventions, and it operates as a protocol-driven platform. It focuses on structured nutrition programs that apply fasting-related research through defined food compositions and fixed program durations.
The brand’s primary category is fasting-based programs built around the patented Fasting Mimicking Diet (FMD). Prolon offers the 5-Day FMD in both Original and Next Gen versions.
According to the brand, each kit contains pre-portioned, plant-based foods including soups, energy bars, snacks, herbal teas, formulas, and extra virgin olive oil. The Next Gen version adds certified organic soups, updated formulations, and ready-to-eat formats. These programs are designed to maintain a fasting-like metabolic state over five consecutive days through specific calorie and macronutrient control rather than complete food avoidance.
Prolon also provides shorter and recurring reset options to support different fasting structures. The 1-Day Reset kit is intended for brief metabolic resets, while the 5:2 Program supports intermittent fasting by providing structured nutrition for two low-calorie days per week. These options extend the same fasting-mimicking framework across varying time commitments without shifting away from the brand’s protocol-based model.
Alongside full programs, Prolon offers the Fasting Bar and Fasting Shake, both designed to be consumed during fasting windows without interrupting targeted metabolic pathways. The brand also offers L-Protein and L-Protein Bars, which may support muscle maintenance while aligning with longevity research principles. Additional products include the L-Pill, positioned for cellular protection and healthy aging support, and the Longevity Spread, a plant-based almond cocoa spread developed within the same nutritional framework.
Prolon has expanded its scope through guided wellness programs that combine nutrition protocols with professional oversight. Its Weight and Metabolic Wellness Program integrates recurring Prolon nutrition kits with one-on-one coaching from longevity-trained dietitians, quarterly bloodwork, and biomarker tracking across several months. Through this structure, the brand extends beyond packaged nutrition into a system that links food-based protocols, coaching, and comprehensive fitness support.
Prolon Bestsellers
Prolon 5-Day FMD
ProLon offers the ProLon 5-Day Fasting Mimicking Diet (FMD), which may help the body enter into a fasting-like metabolic state while still allowing controlled food intake. The program provides pre-measured, plant-based meals designed to significantly reduce calories while maintaining specific macronutrient ratios.
Across the five days, the body is guided through predictable metabolic shifts. During the initial phase, reduced calorie intake leads to the gradual depletion of stored glucose, which is the body’s primary energy source. As these glycogen reserves decline, hormonal signaling begins to shift away from insulin-driven metabolism, preparing the body to rely more heavily on stored fat for energy.
As the program continues, fat oxidation becomes more prominent. With carbohydrates kept low, fatty acids are converted into ketones, which can serve as an alternative fuel source for the brain and muscles. This metabolic transition allows energy production to continue despite limited calorie intake and supports the program’s goal of maintaining a fasting-like state without complete food abstinence.
As per the official website, in the middle of the program, reduced nutrient availability may encourage cellular maintenance processes. One such process is autophagy, through which cells break down and recycle damaged proteins and worn cellular components. This internal recycling system may help maintain cellular efficiency, particularly during periods of metabolic stress or reduced nutrient intake.
The foods included in each day’s box, such as soups, nut bars, snacks, L-drink, products, and teas, are selected to support these metabolic phases. Soups made from vegetables such as tomatoes, carrots, and mushrooms provide fiber, minerals, and phytonutrients that contribute to baseline cellular function. These plant compounds participate in antioxidant signaling and help maintain electrolyte balance during low-calorie intake.
Fasting Shake
The Fasting Shake may provide nourishment while limiting stimulation of nutrient-sensing pathways that are typically activated by higher carbohydrate or protein intake. The formulation emphasizes low-glycemic inputs, moderate fats, and controlled protein levels, which may help support metabolic conditions commonly associated with fasting or time-restricted eating patterns.
Healthy fats in the formula are sourced from almonds, coconut, and macadamia nuts. These fats have monounsaturated and medium-chain triglycerides (MCTs), which are more rapidly converted into ketones compared to long-chain fatty acids.
As per the official website, the shake also provides 21 essential vitamins and minerals that participate in enzymatic reactions across energy metabolism, nerve signaling, and cellular repair. Micronutrients such as B vitamins support mitochondrial energy production, while minerals like magnesium and zinc are involved in hundreds of enzyme systems that regulate metabolic efficiency and cellular balance.
L-Protein
L-Protein is formulated to provide a complete amino acid profile. The protein content comes from pea protein, black bean protein, and chickpea protein, which could support tissue maintenance, enzyme production, and structural protein turnover in the body.
The formula provides 25 grams of plant-based protein per serving of 47g. Amino acids are used for muscle protein synthesis, a process regulated by cellular signaling pathways such as mTOR. They could support muscle repair and ongoing protein renewal, particularly during periods of physical stress or age-related muscle decline.
The protein blend is fortified with L-methionine, which is involved in methylation reactions, antioxidant production, and cellular detox pathways. Methionine may support the synthesis of S-adenosylmethionine (SAMe) that influences DNA methylation, neurotransmitter production, and cellular signaling.
L-Spread
According to the official website, L-Spread is formulated primarily from almonds and cocoa powder, with a high proportion of almonds making up 74% of the total composition. Almonds may contribute to energy intake while limiting rapid carbohydrate absorption. The fat and fiber content in almonds slows gastric emptying, which can moderate post-meal glucose release into the bloodstream.
The primary fats in almonds are monounsaturated fatty acids, which are absorbed and utilized as a stable energy source. These fats do not directly stimulate insulin secretion and are metabolized through beta-oxidation pathways within the mitochondria. This could help lower insulin demand compared to carbohydrate-dominant foods.
The makers also added cocoa powder to this formula, which contributes polyphenols, including flavanols that interact with cellular antioxidant systems. It might help reduce oxidative stress by influencing signaling pathways related to inflammation and endothelial function. Cocoa also contains small amounts of methylxanthines, which can affect cellular energy signaling, though in modest dietary quantities.
Prolon L-Pill
According to the official website, L-Pill can support everyday cellular maintenance. The formulation focuses on nutrients involved in membrane structure, oxidative balance, and cellular signaling.
L-Pill has algal oil, which serves as the primary source of docosahexaenoic acid (DHA), an omega-3 fatty acid. DHA is a structural component of cell membranes, particularly in neural tissue, where it contributes to membrane fluidity and signal transmission between neurons. It also participates in the production of lipid mediators that help regulate inflammatory responses and support cardiovascular and immune signaling pathways.
The formula also includes ProJUVN3T™ wasabi extract (Wasabia japonica root), standardized for isothiocyanates. It may interact with pathways involved in antioxidant enzyme production, including systems linked to cellular stress response and detoxification processes.
PurTea® green tea extract (Camellia sinensis leaf) in this formula could influence oxidative balance by interacting with reactive oxygen species and modulating cell signaling pathways. Caffeine in green tea acts on the central nervous system by blocking adenosine receptors, which can influence alertness and energy signaling at the cellular level.
The formulation uses dual-cap technology to separate sensitive compounds before digestion. This may help protect certain ingredients from early breakdown in the stomach, allowing more targeted release and absorption in the intestinal tract.
Fasting Bar
The Fasting Bar is formulated using nuts and fat-based ingredients intended to provide energy while limiting stimulation of glucose- and insulin-driven metabolic pathways. It contains almonds, coconut, macadamia nuts, and pecans. These nuts may be metabolized through beta-oxidation pathways and do not directly trigger insulin secretion, which may help maintain metabolic conditions associated with fat utilization rather than glucose dependence.
Almonds, macadamia nuts, and pecans primarily supply monounsaturated fats, which are digested more slowly and provide sustained energy release. These fats contribute to satiety signaling by influencing hormones such as cholecystokinin (CCK), which could support appetite regulation during periods of limited food intake.
1-Day Reset
The 1-Day Reset is designed using the same nutritional framework as fasting-mimicking protocols. It features carefully measured plant-based nutrients intended to provide basic nourishment while limiting activation of nutrient-sensing pathways.
According to the official website, the 1-Day Reset is intended for periodic use rather than continuous intake. It can be combined weekly, between longer fasting cycles, or alongside intermittent fasting approaches such as 6:1 or 5:2 schedules. The structure aims to support metabolic consistency while offering a defined nutritional framework for fasting-focused days.
Prolon Advantages
Patented Nutrition Technology Brand
ProLon’s offering centers on its Fasting Mimicking Diet® (FMD®), which the company states is supported by patented nutrition technology. According to ProLon, its parent company, L-Nutra, holds multiple issued patents covering fasting-mimicking diet kits, formulation compositions, and defined methods of use. These patents describe fixed multi-day programs consisting of specific foods, including soups, crackers, nut-based bars, and teas.
Patent filings outline controlled calorie intake combined with predetermined macronutrient ratios. The formulations are described as high in fat, restricted in carbohydrates, and low in protein. The intent, as stated in the filings, is to induce physiological responses commonly associated with fasting while maintaining limited nutrient intake.
The company further references a broader patent portfolio related to longevity-focused nutrition. These documents discuss metabolic pathways such as insulin and IGF-1 signaling, which are associated in the literature with metabolic regulation, cellular stress response, and aging-related processes.
Under this structure, the FMD® is presented as a standardized alternative to unsupervised fasting or general calorie restriction. Patent coverage defines program duration, food composition, and intake limits, creating fixed parameters that distinguish the diet from informal or self-directed fasting practices commonly used in metabolic and longevity contexts.
Physician-Integrated Brand Model
ProLon follows a physician-integrated model rather than a typical consumer diet approach. The brand states that its scientific and clinical direction comes from its parent company, L-Nutra, founded by Valter Longo. His research at the USC Longevity Institute on nutrient-sensing pathways, including insulin and IGF-1 signaling, is cited as the scientific base for the Fasting Mimicking Diet® (FMD®).ProLon licensed physicians actively support and use the FMD® in clinical settings. The brand states that its official site features doctors such as Robert Lufkin. According to the company, these physicians combine the FMD® into metabolic and nutrition-focused care, which the brand presents as professional use rather than consumer experimentation.
ProLon clinical model integrates with healthcare platforms such as Parsley Health. ProLon positions this structure as a way to link nutrition programs with medical oversight. The brand physician-led approach supports credibility, safer use, and adoption within clinical and preventive care settings.
Prolon Limitation
Brand Experience Limited to Cycles
ProLon programs rely on prepackaged, plant-based meals with fixed calorie levels. The goal is to trigger fasting-like metabolic responses, such as ketosis, while still supplying essential nutrients.
The program is designed to be used in cycles rather than continuously. Most clinical studies evaluate outcomes after repeated use, typically three separate five-day cycles spaced across several months. These cycles assess short-term changes in markers such as visceral fat and inflammation, not long-term daily nutrition.
This structure shapes the overall brand experience. ProLon functions as a periodic metabolic reset rather than an everyday eating approach. To align with the research-backed model, you must complete full cycles, which limits flexibility compared with daily products or ongoing diet plans.
Pros
- Prolon offers a patented fasting-mimicking diet developed from longevity research.
- The brand is built around structured, science-based fasting protocols.
- Prolon promotes structured eating discipline through timed programs.
- The brand includes soups, bars, snacks, and drinks in kits.
Cons
- Some customers report headaches or periods of low energy.
- Many users find the value lower relative to the cost in independent reviews.
How Did We Evaluate?
Real Consumer Experiences
To evaluate Prolon, we reviewed Trustpilot feedback from January 2026, where the brand holds a 4.2 out of 5 rating based on more than 9,000 customer reviews. Some users claimed the five-day fasting-mimicking program was easy to follow, particularly appreciating the structured format and pre-portioned meals. Many noticed that having clearly defined daily instructions reduced decision-making and helped them stay consistent during the program. Several users also referenced improved eating awareness, appetite control, or temporary weight changes, especially among first-time users.
At the same time, a few users reported confusion around subscriptions, automatic renewals, post-purchase add-ons, and discount codes. Many customers noticed that website navigation and pricing clarity were not always intuitive, making it difficult to understand what was included in each kit before ordering. A few people also mentioned being charged unexpectedly, which contributed to frustration despite a later resolution.
Some customers claimed that packaging inconsistencies occurred, such as missing options or incorrect soup combinations, particularly among households that ordered multiple kits. Many users noted that customer support usually addressed these issues quickly, though the frequency of such errors was raised as a concern by repeat purchasers.
Several long-term users stated that food variety became limited after multiple cycles. Some customers mentioned taste fatigue, lack of customization options, and inability to select specific soups or bars, which reduced long-term appeal even when the program itself was viewed as effective.
Many customers highlighted customer service as a consistent strength. Some users claimed support teams were responsive, patient, and effective in resolving shipping issues, refunds, and order corrections. Even among critical reviews, customers often acknowledged that assistance was provided once contact was made.
This evaluation showed that most users had positive experiences with Prolon, with a few recurring concerns around transparency, customization, and operational clarity.
Brand Credibility
We evaluated Prolon by reviewing its product focus, corporate background, and available third-party credibility indicators. The brand operates within the structured nutrition segment, with its primary emphasis on a fasting-mimicking dietary protocol. Its core offering is a five-day program consisting of pre-portioned plant-based soups, nutrition bars, herbal teas, formulas, and hydration components.
Prolon itself is not currently listed with the Better Business Bureau and does not hold an individual BBB rating or accreditation. However, its parent company, L-Nutra, maintains an A+ rating with the BBB, under which consumer complaints related specifically to Prolon are recorded. Several complaints associated with Prolon were filed over the past years, primarily falling under sales and advertising issues, billing concerns, subscription management, and customer service response delays.
These complaints indicate that issues often involve promotional pricing interpretations, subscription cancellations following website changes, and delays in initial customer support responses.
On Tenereteam, Prolon holds an average rating of 4.5 out of 5, based on 1900+, showing mostly positive feedback. Users state that they like the convenience and short-term weight management of the 5-day program. However, many mention the high price and say results often don’t last without repeating the program.
Prolon appears to operate as a structured, protocol-driven nutrition brand with an established parent company and documented customer engagement processes. The presence of resolved BBB complaints linked to Prolon suggests active response mechanisms, though recurring concerns around pricing transparency and subscription management indicate areas that may require continued clarity.
Frequently Asked Questions
Yes. The brand provides ongoing nutritional coaching through its Metabolic Reset Program. This option includes one-on-one sessions with a longevity-focused dietitian, monthly check-ins, and structured guidance over several months, extending beyond the standard 5-Day Fasting Mimicking Diet.
The brand requires adherence to its daily meal structure rather than fixed eating times. Its program provides precisely formulated day-specific meals, such as Day 1 transition and Day 3 autophagy support, which must be fully consumed within that day to maintain the intended metabolic sequence.
No. The brand does not allow food substitutions during its programs. It states that meals are precisely formulated to maintain the fasting-mimicking state, and replacing kit components, including options like the L-Bar, may disrupt the intended metabolic and autophagy-related effects.
Conclusion
ProLon operates as a structured nutrition program centered on a fixed sequence of plant-based meals with predefined calorie and macronutrient ranges. It highlights that its program can influence nutrient-sensing pathways involved in metabolic regulation, including insulin signaling, IGF-1 activity, and mTOR response.
However, the brand’s protocol does not adjust for body composition, activity level, or metabolic differences, which can affect tolerance and adherence. Before starting, you should approach the plan with caution if you have blood sugar sensitivity or follow high-intensity training schedules. Using the brand’s offerings too often, combining it with caloric restriction outside the plan, or considering it as a replacement for balanced nutrition may increase risk rather than benefit.
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Alisha Matthew has been a practicing nutritionist since 2016. She holds a master’s degree in nutrition from the University of IOWA. She is a staunch believer in improving the human health index by educating people about nutrition and the importance of nutrition in leading a healthy and happy life. Her long-term goal is to keep educating people on general health and keep herself updated with the latest trends in the field of health.