Prolon is a science-driven nutrition brand focused on supporting healthy aging and longevity through evidence-based nutritional programs. Its flagship product, the Prolon 5-Day Diet, is a patented Fasting Mimicking Diet (FMD) developed from more than 25 years of research and 40+ published clinical studies conducted in collaboration with USC, Mayo Clinic, and Stanford, to help the body enter a fasting-like state while still providing carefully formulated nourishment that supports natural cellular renewal. The 5-Day Diet is a complete, pre-packaged nutrition program that includes portioned meals, snacks, and beverages for each day, making the experience simple to follow without calorie counting or meal planning. Clinical research published in peer-reviewed journals, including Nature Communications, found that participants completing three consecutive monthly cycles experienced an average 2.5-year reduction in biological age markers, while also supporting healthy metabolism, preserving lean muscle, and promoting fat loss. But the 5-Day Diet is only the beginning. The same decades of longevity research that gave rise to the FMD also informed Prolon's broader ecosystem of science-backed products designed for everyday life. This includes L-Biome, a precision probiotic formulated to support gut health and metabolic function; fast bars, developed to extend the fasting state between meals; nutrition shakes built around longevity-supporting protein ratios; and guided reset programs that combine multiple Prolon products into structured, longer-term health protocols. Every product in the Prolon line shares the same origin, rigorous peer-reviewed science, and the same goal: to give your body what it needs to function better for longer. Founded on the belief that nutrition should be grounded in rigorous scientific research rather than trends, Prolon develops all of its products using a research-first approach. Prolon is part of L-Nutra, a nutrition technology company dedicated to advancing evidence-based nutrition for healthy aging and longevity. Our mission is to make cutting-edge longevity science accessible to everyone because how you age is not simply something that happens to you. It is something you can actively shape.
Written by the business, not verified by us.Prolonlife (prolonlife.com) has a 4.2 out of 5 rating on OK.one, based on 201 user reviews collected here. It is listed under Beauty & Well-being and its reputation is good. 77% of reviews are 4 stars or higher and 8% are 1 star; The business has replied to 97% of negative reviews; Reviews mostly discuss Product, Quality, User experience. Last updated 2026-08-12.
Reviewers had a great experience with this company. Customers frequently highlight the exceptional quality and delicious taste of the products, noting that the structured daily routines make fasting surprisingly satisfying and easy to follow. Consumers consistently praise the professional guidance and responsive customer service representatives who quickly resolve questions and assist with purchases. However, some reviewers were not happy with ordering complications, mentioning unexpected subscription renewals and difficulties managing automated shipments. A few other people also felt that certain food flavors were unappealing or grainy, while others reported frustrating shipping delays. Some individuals additionally experienced missing components in their delivered kits or found specific snack items difficult to enjoy.
Auto-generated from all reviews of this business. For reference only.The website was not easy to navigate. I couldn’t find a complete list of what was in the fasting kit and what the difference packages/flavors were. The only way I found a detailed explanation of the flavors was by taking the quiz. Only then were all the details spelled out.
I tried to cancel my subscription many times but just kept having issues with the website.
Hi Heather, Thank you for taking the time to share your experience. We truly value your feedback and are committed to providing the best possible experience with Prolon. We’re sorry to hear about the difficulty you experienced while trying to cancel your subscription. We’re glad we were able to cancel your subscription and help manage your account according to your preferences. Our Customer Service Team has also reached out to you directly from [email protected] to clarify what happened and work with you toward a resolution. Your feedback is important to us, and we’re committed to making the process as smooth as possible. We appreciate the opportunity to better support you and look forward to assisting you further.
I love this program. The hardest thing about doing a fast is getting started. It helps to have a structured protocol and support. The online coaching sessions are invaluable. They make the cost worth it for the product. I have done 24 rounds. They have kept my weight normal and my general health to be excellent despite being over 70 years old.
Hi Ruth, Thank you so much for sharing your experience with us! We’re especially grateful to hear how much the structure and coaching support have helped you stay consistent throughout your journey. 24 rounds are incredible! It means so much to know that Prolon and our coaching sessions have become a valuable part of your wellness routine and have helped you stay on track with your goals. We’re honored to be part of your journey and truly appreciate your continued trust in Prolon. Here’s to many more healthy rounds ahead! Please don't hesitate to reach out if you ever have any questions. We are here for you.
Davis customer service was excellent and the company was extremely helpful and helping me determine a plan within my food sensitivities. I greatly appreciated all their efforts.
Hi Chris, Thank you so much for your wonderful feedback! We’re so glad to hear that David was able to provide excellent support and help you navigate your options based on your food sensitivities. We know that everyone’s wellness journey is unique, and we’re grateful for the opportunity to support you along the way. Thank you for choosing Prolon, and please don’t hesitate to reach out if you ever have any questions or need anything. We’re always here for you!
Customer service was awesome! Problem resolved quickly & even better than imagined. Great support!
Hi Kim, Thank you so much for taking the time to share your experience! We’re happy to hear that our team was able to support you and help find a solution that worked best for your needs. Providing personalized guidance and making sure our customers feel supported is always our goal. We truly appreciate your kind words and are grateful to have you as part of the Prolon community. Please don’t hesitate to reach out if there is anything else we can assist you with. We’re always here to support you!
I did not subscribe to get automatic shipments. I've contacted customer service but did not receive a reply. I do not want the product that is being delivered.
Hi Lea, Thank you for taking the time to share your experience. We truly value your feedback and are committed to ensuring you have the best possible experience with Prolon. We understand that subscription details can sometimes be easy to overlook, and we’re grateful that our system allows us to review the account history and better understand what may have happened. Our goal is to use that information to help find the best way forward for you. Our Customer Service Team has already reached out to you directly from [email protected] to help address your concerns, clarify what happened, and work with you toward a resolution. Thank you for giving us the opportunity to assist you. Your satisfaction is very important to us, and we look forward to hearing from you and having the opportunity to support you further.
I never thought I could do a 5 day, even modified fast, but the kit makes it extremely easy, and amazingly I did not feel deprived. The snacks are actually tasty, small, but savorable. I did the soups you need to reconstitute with water, and found them savory, and enjoyable. I recommend adding the water slowly, in increments until you get the consistency you want. It allows you to reset, slow down, and the science behind it is solid. It is expensive. But it is replacing 5 full days of meals. I wish my budget allowed me to do it more often. They do offer support during your fast and make it relatively simple to skip subscription shipments, and they clearly tell you when the next charge will occur. I have been proactive about this due to the high cost of the product so I am not completely sure if they warn you if a shipment is coming up. I set reminders in my phone.
Hi Shereen, Thank you so much for taking the time to share such thoughtful feedback. We’re thrilled to hear that Prolon helped you complete a 5-Day Fast and that you found the program easy to follow, satisfying, and enjoyable. We appreciate you sharing your preparation tip as well! Adjusting the water gradually to find your preferred soup consistency is a great way to personalize the experience while staying within the program guidelines. We’re also grateful that you highlighted the science behind the program and the support available throughout the journey. Thank you for trusting Prolon and for being part of our community! Please don’t hesitate to reach out if you have any questions or if there is anything we can assist you with. We’re always here to support you.
Prolon made the five day fast easy. Kids easy to use, food was very satisfying. Felt great during an afterwards. A great jumpstart to better health!
Hi Rebecca, Thank you for sharing your experience with us! We’re so happy to hear that the Prolon 5-Day Fast helped make your fasting journey feel approachable, satisfying, and manageable. We love hearing that you felt great during and after your fast. Supporting people with a structured approach that helps them feel confident while working toward their health goals is exactly what we strive for. Thank you for choosing Prolon and for sharing your journey with our community! Please don’t hesitate to reach out if there is anything we can support you with. We’re always happy to help along your wellness journey.
Prolonged shakes are terrific! I enjoy the berry flavor and add fresh berries often. My energy is sustained through the AM including days I go to 45 minute reformer Pilates class and/or the gym. I am 72 year old female. Never disappointed with any Prolon product.
Hi Karen, Thank you so much for sharing your wonderful experience with us! We’re excited to hear that you’re enjoying the Berry Longevity Protein Shake and love that you’ve found a routine that supports your active lifestyle, including Pilates and gym sessions. It’s amazing to hear that Prolon has been part of your wellness journey, and we truly appreciate your continued trust in our products. Thank you for being part of the Prolon community! Please don’t hesitate to reach out if you ever have any questions or need any support. We’re always here for you.
The 5-day program was easy to complete if one is dedicated to better health. The pre-made soups are good. The crackers and snack bars are satisfying. The tea is nice as well. The change I would make is with the olives. I do not eat olives, but I substituted a tablespoon of olive oil in my soup. I will do the 1-day reset every month until I do the 5-day program in the future. I lost 5 lbs and have kept it off.
Hi Claudia, Thank you so much for sharing your experience with us! We’re thrilled to hear that you found the 5-Day Program easy to complete and that the pre-made soups, crackers, snack bars, and tea helped make your experience enjoyable. We appreciate you sharing your olive substitution as well. We understand that taste preferences can vary from person to person. For the best experience and to align with how the program was studied in our clinical trials, we do recommend following the Prolon meal plan as closely as possible. To help accommodate different preferences, we created our Next Generation Prolon Kits, which offer a wider variety of options, including versions with extra-virgin olive oil in place of the whole olives. We hope these options help make the experience more enjoyable while still supporting the structure and goals of the program. Congratulations on your progress and on losing 5 lbs while maintaining your results! It’s wonderful to hear that you’re incorporating the 1-Day Reset into your routine and continuing to support your health journey. Thank you for choosing Prolon and for sharing your experience with our community. Please don’t hesitate to reach out if you have any questions or if there is anything we can support you with. We’re always here for you.
It’s easy to change your subscription whether you want to skip a shipment or have it sent earlier. Thanks for making it easy!
Hi Jackie, Thank you for sharing your experience! We’re so glad to hear that managing your subscription has been a simple and convenient process. We understand that life and schedules can change, and we want to make it as easy as possible for customers to adjust their subscriptions when needed. Thank you for being part of the Prolon community! Please don’t hesitate to reach out if you need any help with your subscription or have any questions. We’re always here for you.
Great customer service. Clean, quality ingredients. Shakes are delicious!
Hi Tammy, Thank you for your wonderful review! We’re so happy to hear that you’re enjoying the quality of our products, the ingredients, and especially the Longevity Protein Shakes. Providing clean, thoughtfully formulated products along with supportive customer care is something we truly value. We appreciate you taking the time to share your experience with us! Please don’t hesitate to reach out if you ever have any questions or need assistance. Our team is always here to support you.
It was difficult to find the details of the program and the science behind it. Before you provided that information, I was being asked to make a purchase decision. After several clicks, I was able to satisfy my questions. I have had some education on FMD diets and wanted to make sure the information was in alignment with my understanding.
Hi Lynne, Thank you for taking the time to share your feedback. We truly appreciate you sharing your experience and your desire to better understand the science and research behind Prolon before making an informed decision. We understand how important it is to have access to clear, comprehensive information when exploring a program like this, and we appreciate your feedback as it helps us continue improving the way we communicate our research and resources. Our Customer Service Team has reached out to you directly via email from [email protected] to learn more about your experience and gather additional feedback on how we can better support customers seeking more information about the program. Your feedback is incredibly valuable to us, and we appreciate the opportunity to continue improving the customer experience. We look forward to hearing from you.
I had difficulty ordering online, so I called & reached Manuel, who did an outstanding job helping me order. You have a star player in him! **********!
Hi Julia, Thank you so much for sharing your experience! We’re happy to hear that Manuel was able to provide excellent support and make your ordering experience easier. We’ll be sure to share your kind words with him. We’re lucky to have team members who are dedicated to helping our customers feel supported every step of the way. Thank you for choosing Prolon! Please don’t hesitate to reach out if you need anything in the future. We’re always here to help.
I had done Prolon before - it was gifted to me and it was fine. I didn't love the L bars but there was some variety and soups ok. This I believe was earlier versions as it came with the water bottle. I ordered the GEN3 boxes did the deal for two. February 5, 2026 - A regretful mistake. I did not realize it came with all the same L-bars which are disgusting. In my opinion it is not clear in the description that that you are getting all the same type. Some of the soups are pretty bad too despite the descriptions making them sound appealing. Tried adding a bunch of herbs to disguise the taste but they still icky. Unfortunately I feel for the sale and packaged with the fasting shakes and just haven't had the will to open them due to the 5 day experience. They also have a short shelf life - they were BB June and I ordered February 5, 2026 - Delivery February 11, 2026 The l-bars being all the same flavor is just horrible and I feel that with the general consensus online being they are not palatable leading to consumers coming up with creative ways to try make them taste better says a lot. You would think with the number of l-bars in the 5 day fast it would naturally come with a variety. I would have paid more to get the the variety if it had been clear which I am sure Prolon banks on. For me the standard Lbar is sickly unusual sweetness, they have a bitterness to them and leave a coating in your mouth. I did not want to eat them and probably wont when I punish myself and do the second box. - Prolon says you can skip them - haha they know people, they know! The second box is currently sitting atop my cupboard taunting me with it's impending BB date! I was very disappointed with my experience.
Hi Amanda, Thank you for taking the time to share your experience with us. We truly appreciate your detailed feedback and the opportunity to better understand your perspective. We sincerely apologize that your recent experience with Prolon did not meet your expectations, particularly regarding the flavors and overall enjoyment of the program. We understand how important taste and variety are when completing a 5-day program, and we appreciate you sharing these details with us. Our Customer Service Team has reached out to you directly via email from [email protected] so we can better understand your experience, answer any questions you may have, and explore ways we can support you moving forward. Your feedback is incredibly valuable to us, and we are continuously working to improve our products and customer experience. We appreciate the opportunity to connect with you and hope we can help make your future experience with Prolon a more positive one.
I have done this fast 4 times. The good side is I have lost 4-5 lbs each time, the bad side is it’s truly hell and not because you’re suffering from hunger, but because the taste is so intolerable. I often skip some of their food just because not eating is more appealing. I don’t think I can do it again, but if they can manage to alter their flavors somehow, I’d definitely reconsider bc the benefits are great.
Hi Daniela, I’m reaching out to you personally regarding the review you recently shared with us. My name is Jennifer, and I’m a nutritionist here at Prolon. First, I want to sincerely thank you for taking the time to share such honest feedback about your experience. I truly appreciate you sharing both the positive and challenging aspects of your Prolon journey. It’s wonderful to hear that you have completed the program four times and experienced positive results, but I’m sorry to hear that the taste and flavor experience made the process so difficult for you. We understand that taste preferences can vary greatly from person to person, and completing a 5-day fasting program is already a commitment. We want the experience to feel as enjoyable and sustainable as possible, so your feedback regarding the flavors is incredibly valuable to us. I would love the opportunity to better understand your experience and learn more about which products or flavors were the most challenging for you. Our Customer Service Team has already reached out to you directly via email from [email protected] to help address and clarify your concerns and work with you toward a resolution. Your feedback helps our team continue improving our products and ensures we are considering the experiences of customers like you. We’re grateful that you shared that you’ve experienced the benefits of the program, and we truly appreciate your continued trust in Prolon. We would love the opportunity to support you and make your future experiences as positive as possible. Thank you again for taking the time to share your thoughts. We’re here to listen and support you.
I typed my response in already. Why did you delete it? Issue with ordering. Did not allow me to complete my order. Prices have increased considerably. Smaller discount.
Hi Kathy, Thank you for taking the time to share your experience. We truly value your feedback and are sorry to hear about the frustration you experienced while placing your order. We sincerely apologize for the inconvenience you encountered with the website, as well as for any confusion regarding our pricing and subscription discounts. This is certainly not the experience we want for our customers. Our Customer Service team has already reached out to you directly via email from [email protected] so we can better understand what happened, address your concerns, and work with you toward the best possible resolution. Your satisfaction is very important to us, and we are committed to making your experience as smooth and positive as possible. We truly appreciate your feedback, as it helps us continue improving both our website and the overall customer experience. We look forward to hearing from you and to the opportunity to support you further.
Several times, the check out failed and registered a 404 error.
Hi Denise, Thank you for taking the time to share your experience with us. We truly value your feedback and are committed to ensuring our customers have the best possible experience with Prolon. We sincerely apologize for the inconvenience and frustration you experienced while attempting to complete your checkout. We understand how disappointing it can be when technical issues prevent you from placing your order successfully. Our Customer Service Team has reached out to you directly via email from [email protected] so we can better understand what happened, assist with your concerns, and work toward a resolution. Your feedback is very important to us, and we appreciate the opportunity to look into this further and improve your experience with Prolon. We look forward to connecting with you and providing support.
I liked the insurance on my Prolon product, unfortunatley I was unable to complete a fast because of health issues. I was able to get a refund on my purchase. I have completed 3 fasts and my age and the issues that come with it prevented me from particitpation
Hi Celia, Thank you so much for sharing your experience, Celia. We're sorry to hear that health concerns prevented you from completing another fast, but we're glad we were able to assist you through your Onward Order Protection benefits. Your health and well-being always come first, and we appreciate the trust you've placed in Prolon over the course of your three fasting cycles. Thank you again for your kind words and for being part of the Prolon community. We wish you all the best, and if there's ever anything we can do to support you in the future, please don't hesitate to reach out.
I needed to give a new cc number and get my deliveries set up again and she did exactly what I needed .
Hi Deborah, Thank you for taking the time to share your experience! We're so glad we could help update your payment information and get your deliveries set up again quickly and smoothly. Providing personalized, efficient support is always our goal, and we're happy to hear we were able to make the process easy for you. Thank you for choosing Prolon, and we look forward to continuing to support you on your longevity journey!
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