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ProLon Review - 15 Things You Need to Know

ProLon is a 5-day meal program that aims to boost your health with ‘scientifically developed foods.’ Its proprietary blend of ingredients claims to put your body in fasting mode, which scientific evidence suggests might be an effective form of weight loss. That being said, this program is not for everyone, and it could be dangerous to people with a low BMI.

Due to its intensity, our research team found that the program has strict guidelines and needs the approval of a medical professional before use. We examined ProLon’s components, side effects, and the testimonials of its users to get to the bottom of this weight loss program. Here’s everything we discovered.

ProLon can be purchased through their Official Site.

ProLon Readers: Noom is offering our readers a risk-free trial, for a limited time. Click here for more information!

What is the Prolon?

First of all, ProLon is a 5-day meal program designed to nourish the body while “promoting regenerative and rejuvenating changes through scientifically developed, plant-based foods.”

Each meal comes in a box- one for each day (around 750 to 1100 calories per day). Inside these boxes, you’ll find a cornucopia of healthy, plant-based energy bars, snacks, supplements, beverages, and soups.

After the five days, the dieter is supposed to “transition for one day” and then go back to their regular routine.

The website claims that all of their food is scientifically studied and proven to give your body exactly what it needs to be as healthy as it possibly can, but what does the science specifically say about fasting?

  • CMAJ – There are some concerns with fasting, as individuals may “binge” during periods of time when eating is allowed.
  • PLOS One – Periodic fasting between 4 – 21 days is considered safe and can provide some benefits to emotional and physical well-being.
  • International Journal of Health Sciences – Intermittent fasting can provide a number of benefits to the body, like reduced chance of developing certain health conditions.


What is a Fasting Mimicking Diet?

This “Fasting Mimicking Diet” allows you to get all of the amazing benefits of fasting without skipping your meals. You stay fuller, longer. They also claim that their foods promote positive changes within your body while making the fasting-mimicking period fun and safe for the customer.

We have to say, at first glance, we’re hopping on this wagon – scientific research and natural foods are a pretty good start in our eyes. But if you know us at all, you’ll know we’re not done until we get all the facts.

Products Similar to ProLon

Company Bio

The Company Behind ProLon, L-Nutra

The company behind this fasting-mimicking diet is called L-Nutra. L-Nutra is headquartered in California and has been around since 2009. Their address is 2034 Armacost Ave, Los Angeles, CA 90025. You can contact their customer service Monday through Friday from 9 am to 5 pm CST at +1 888.618.1281, or email them at support@l-nutra.zendesk.com. They earned a rating of “B+” from the BBB. While there are no customer reviews, there has been one complaint closed in the past year.

We scoped out their website and were impressed by the outstanding claims of scientific research and support from the National Institute for Aging and the National Institute of Health.

Their meal plans emerged after 20 years of research from the University of Southern California. They also claim their preclinical and clinical trials are performed at institutes like the University of Berlin, Mayo Clinic, Leiden University, and the University of Genoa.

The company offers an affiliate program for their products. Other products by L-Nutra Inc are Fast Bar and Nutrition for Longevity meal plans.


ProLon Ingredients

Since this is a proprietary diet, there’s not a complete list of ingredients. As we do understand this, it leaves a slightly bitter taste in our mouths. We like to know exactly what we’re getting.

We did put in some work and came up with the most detailed ingredient list that we could.

They offer nut bars that list ingredients such as macadamia nut butter, pecan, almond meal, honey, coconut, flaxseed meal, coconut oil, vanilla extract, sea salt, citric acid, ascorbic acid, mixed tocopherol.

Their Kale crackers consist of Golden flax seeds, kale, cashews, sunflower seeds, sesame seeds, nutritional yeast, apple cider vinegar, hemp seeds, dill weed, pumpkin seeds, sea salt, black pepper, and onion powder.

Their drinks contain natural vegetable glycerin, purified water, potassium sorbate, and natural flavor.

They offer a bevy of soups, containing combinations of;  tomato concentrate, rice flour, potato starch, leek, quinoa, onion, olive oil, parsley, peas, yeast extract, savoy cabbage, carrot, zucchini, garlic, spinach powder, broccoli powder, sage, Champignon mushroom powder, celery, and turmeric.

The second variety of soups are butternut, tomato, butternut quinoa, white bean & spinach, and black bean.

Their dessert (Choco crisp bar) is made of brown rice, inulin, almonds, almond butter, cocoa powder, brown rice syrup, chocolate chips, rolled oats, rice dextrin, flaxseed oil, salt, and grape juice.

We’ve seen some lists of ingredients that vary slightly from what we came up with; again, this is a proprietary diet, and the ingredients aren’t all that certain.


How to Use (Take) Prolon

The healthy diet Prolon and exercise are in collaboration and need be taken for five back-to-back days, after which the user will progress for a day and resume their ordinary eating routine.

Guidelines and proper instructions are given in each package. A particular blend of nourishment is given every day for lunch, breakfast, supper, etc.

All nutrition given on a particular day must be used that day, as it were.

While a healthy meal missed can be set aside a few minutes during that day, there should be no trace starting with one day then onto the next.

The 5-day Prolon diet needs to be taken as regularly as is prescribed by the guidelines on the box.

The 5-day Prolon FMD can be purchased from different suppliers. Prolon prices range from $200 to $270 depending on your location and distributor.

Prolon claims


Prolon Claims

Prolon claims to be the primary Fasting Mimicking Diet that gives you a blend of ingredients and foods ready to reinvent the body into a recovering and restoring mode, bringing about a balance and aging healthy.


Benefits of ProLon

So, what are the benefits of this fasting diet? We’ll list a few for you:

  • Regenerate: ProLon triggers a “natural multi-system regeneration,” which includes various benefits from anti-aging and more.
  • Speedy Weight-Loss: No extraordinary claim would be complete without the promise of quick and easy weight-loss. This is exactly what ProLon offers – except they say they have some scientific research to back it up.
  • Convenience: Of course, this diet is as convenient as anything. Each meal comes in its own “grab-and-go” box, making it simple to follow and even easier to access.
  • All-Natural: As we stated earlier, the ingredients and foods in this diet are all-natural, using plant-based ingredients like fruits, nuts, seeds, and veggies.

Prolon side effects

Side Effects

Potential Prolon Side Effects

In the study and research analysis, most members proclaimed few minor or no unfavorable side effects for the fasting days, although none of these side effects were indicated.

In any case, the organization highlights in a few places that Prolon isn’t for everybody and should just be utilized by adults over age 18, and they should be healthy and strong.

Outside of what’s provided in each box, the organization underlines that no extra multivitamins or supplements must be taken within the fasting or diet period.

Also, unless stated by an authorized doctor, Prolon should never be used with any medications.

Prolon weight loss

Weight Loss

Details on Prolon and Weight Loss

The 5:2 diet (in taking just 600-700 calories two days per week) aids with weight loss and the company claims the body desires to fast for a good long period without eating so that it goes into safe and secure mode, which is how human beings survived for tens of thousands of years.

The advantages of ensuing an FMD are countless: although weight-loss will unquestionably happen, the key aim is to cover your Life Span-Aging – that is, just how long you live a comfortable and healthy life, before facing any aging disorders.


ProLon Cost

ProLon seems to be only available for purchase on the official website and potentially through your doctor. On the official website, the different purchase options are:

  • 5-day dietary program
    • Subscribe & Save $179 (includes free shipping)
    • Single ProLon Box $187 (includes free shipping)
    • 2 Box Bundle & Save $330 (includes free shipping)
  • 1-Day Reset
    • First Time Faster
      • Single Box $39.99
      • Subscribe & Save $35.00
    • Fasting Lifestyle
      • 2 Box Bundle & Save $75.00
      • 2 Box Bundle Subscribe & Save $70.00
    • Advanced Fasting
      • 4 Box Bundle & Save $140.00
The Science

The Science of ProLon

If I were writing a book right now, it would be called The Science of ProLon; I would have no shortage of scientific studies and research to fill my book to the brim.

The L-Nutra website claims there’s research backing everything – the company even offers relevant science, similar to the research backing the Sirtfood Diet.

Prolon research

It went on to say that three cycles of 5-day fasting-mimicking diet were deemed safe and effective.

Remember when ProLon claimed it could help regenerate your body? There is a study with some pretty interesting findings.

Now, we realize that not all of the studies are about this diet specifically, but if you’re anything like us, you seriously appreciate some solid research behind a product’s claims.

Where to Buy

Where to Buy Prolon

Things get a bit tricky when you consider purchasing this diet plan for yourself. You can’t exactly hop on Amazon and purchase this program – you need to pass a test of sorts. You can check the official website for more information.

That’s right; there are extraordinary claims and unbelievable scientific backing ProLon. But, not everyone can purchase it – there’s an exclusion criterion. Speak with a physician before starting anything.

After speaking with a doctor, approval for ProLon comes in four ways:

Take a Health Self-Assessment Survey

Take a survey to find out if ProLon mimicking diet is the right choice for you. After taking the survey, it may tell you that you need to speak with a doctor first. If you meet the criteria, the only other step is to schedule a phone call with a dietitian or nurse practitioner.

Health Care Provider Evaluation

You can call the ProLon information line, speak with a professional, or get approval from your physician.

Use the HCP Code from a Health Care Provider

Once you speak with a doctor, they will provide you with a code. Use this code to finish your registration and to order your ProLon.

Doctor’s authorizations and approval codes.

No Medical Conditions

There is an option to check that you have no medical condition or age restriction preventing you from trying Prolon.

Prolon warnings

Product Warnings

Prolon Product Warnings

Prolon is not considered safe for all dieters. According to the official website and information on fast mimicking diets, individuals should not consume ProLon products if they are:

  • Under 18
  • Sensitive or allergic to soy, nuts, celery, sesame, or oats
  • Pregnant
  • Have different dietary needs that are mismatched with the Prolon meal diet
  • Suffer from any medical condition or sickness
  • Have Body Mass Index (BMI) less than 18
  • Protein-Deficient

When you are following this plan, you should be under the supervision of your doctor the entire time.

Reddit Reviews

Prolon Reddit Reviews

Reddit is one of the top 10 social media websites and is filled with passionate users and commenters. On average users spend more than 10 minutes on Reddit per visit to learn more about an endless number of topics, including supplements, pre-workouts, and meal replacements. We researched Prolon Reddit reviews to learn what the community had to say.

Among the Prolon Reddit reviews, some users loved it, but others weren’t convinced. It’s love/hate on Reddit when it comes to the reviews. There are a few users who express concerns about inulin, the active ingredient because it has been associated with digestive discomfort.

What Users Are Saying

What Users Are Saying

“My husband and I have been using ProLon for a year now and have had wonderful results. We are retired and found that we were having a very hard time with our weight. We exercise, but it was not enough. With ProLon we are able to lose weight.”

“Prolon is a great concept. I liked the nut bar, but the rest of the food is absolutely disgusting and causes bloating. I felt horrible until the 5th day. So basically you pay someone $200 to feel awful and eat gross food. Probably be easier and healthier frankly to eat nothing but vegetables for five days. But that’s just my two cents.”

“Does not work for weight loss. I didn’t lose any weight. I actually gained weight the first day. I don’t understand how this is possible based on the number of calories alone but I also didn’t lose any inches in my belly, it actually got bigger.”

Bottom Line

The Bottom Line on ProLon

If you asked yourself, “Is ProLon for me?” you wouldn’t be alone. We’ve noticed a large amount of interest surrounding this diet. There are also bloggers and reviewers chomping at the bit wanting to try it out for themselves. But, we’re just not 100% sure.

Of all the means of losing weight, making lifestyle changes tends to be the most effective. However, long-term lifestyles changes are difficult and can make it hard to stick with a plan. That’s where we found technology picks up offering continuous support.

Among the best weight-loss apps we’ve seen is one called Noom. Noom works with experts and medical doctors to create a platform with personalized meal plans, an extensive food database, real human coaching, and so much more.

Dietspotlight Readers: You can access a free trial offer today to give Noom a try.

Learn More About Noom »
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What are the side effects of ProLon?

There aren’t any real side effects associated with ProLon. This is a fasting type of diet so hunger pains and headaches associated with hunger may be the worst side effects.

Does ProLon work?

The ProLon works because it causes a calorie deficit. This is a short-term only weight loss solution, not a long-term.

How much does ProLon cost?

5-day dietary program

  • Subscribe & Save $179
  • Single ProLon Box $187
  • 2 Box Bundle & Save $330
    *All option in this program includes free shipping.
Where can I buy ProLon?

You can purchase ProLon on the Company’s website at https://prolonfmd.com. You can’t purchase on Amazon; however, you can purchase the books related to the ProLon diet.

How should I take ProLon?

Since there are so many components to ProLon you have to read each item individually to get the instructions. Preparing the soup versus the dessert is going to be different.

Where can I buy ProLon?

ProLon can be purchased using their Official Site.

How do I contact ProLon customer service?

You can contact customer service by calling or sending them an email. They also have a contact form on their site where you can message them and wait for a reply.

Can I return ProLon?

The company does not accept return or exchange of Prolon kits because of food safety and customer protection.

What are the most common complaints about ProLon?

The main complaint about the ProLon is the price for only a short-term weight loss diet. You do get a lot of product but the price is extremely high.

Can you drink coffee on ProLon?

Although ProLon does not recommend consuming coffee while on their program, 1 cup a day is allowed.

What do you eat on the ProLon diet?

While using ProLon, users will eat 5 of their pre-packaged meals a day and nothing else. Users will do this for 5 days.

How often can you do ProLon?

How often you can do ProLon will depend on your needs and the recommendations from your healthcare professional. The average number of times ProLon is used is 3-4 times a year, though others may do the program up to 12 cycles a year.

What is the ProLon fast?

ProLon’s products are designed to help users mimick the fasting effect in the body without having to stop eating.

27 ProLon Reviews

  • Costly and ineffective
    Allison Spittler (Verified Purchase)

    Extremely expensive, and poor customer service…the daily soup regimen tastes like garbage…pass on this product for sure!

  • Scott

    So this is my 2nd time using Prolon. !st time I lost 8 pounds this time I’m seeing about 5 lbs lost. The Diet has 1 negative some of the soups are just terrible. Prolon should offer a small sample kit or allow user’s to select their soup choice. This would allow user’s to know what to select for their kits. Besides that I can’t complain I have had worst meals..

  • Beware of heart arrhythmias caused by this diet
    Rose (Verified Purchase)

    Low protein and very low calorie diets cause heart arrhythmias, including Afib. Prolon doesn’t warn about this at all. On day 2, I started having a thumping heart and lots of skipped beats, for a couple of hours. I did a google search and found on the Cleveland Clinic site that this is caused by low protein and low calorie diets. I ate a big handful of mixed nuts and drank an electrolyte drink, and the skipped beats stopped within an hour. I have experienced arrhythmias before but hadn’t had any in a long time, until I tried this program. So beware. They tout all of the heart health benefits, but don’t warn you. I contacted Prolon and they were very dismissive. L-Nutra only used to make this available with the consent of your doctor, but greed got in the way, and now anyone can buy it. Warnings are inadequate.

    Asha (Verified Purchase)

    Way too expensive for what it is, and I’m saying that only having paid $145. I plan to do FMD again but have found an article online by a nutritionist with has comparable meal plans. It is a fraction of the price as you put the meals together yourself.
    By biggest complaint about the soups on ProLon is that they are dehydrated. My body has no idea what to do with this as I NEVER eat this way. The gas is unbearable, and after the second soup, I had no choice but to buy and then take 3 Beano before consuming these.
    Normally I eat whole veggies/fruits/grains and I make beans from scratch and never have this issue!

  • Intestinal Stress
    Wendy Chase (Verified Purchase)

    I had really bad intestinal cramping and bloating on day 5. So much so that I couldn’t sleep. I am still having it on day 6. I’ll never do Prolon again.

  • Did not lose any weight
    Melissa (Verified Purchase)

    I am beginning day 5 and I have lost 1/2 of a pound. I have followed this diet exactly. I do feel energetic, and clear minded but I am so disappointed with no weight loss. Has anyone else experienced this?

  • Prolon helps with calorie-restriction after the fast
    Marsha M Huber (Verified Purchase)

    I’m on my second time using Prolon. The first time, I could barely stomach the soups. The protein bars, crackers, and olives are something to look forward to. I ordered the alternative soups this time, and they are better. I’m very hungry tonight though. Last time, I didn’t get hungry until Day 5. This time I am hungry on Day 3. Let’s see how it goes.

    Anyway, I may have have lost a pound or two the first time I did Prolon, but I was able to keep on a calorie restricted diet (1,200 calories) afterward. I lost about 10 pounds since 8/25/2020, which is about 6 weeks. I also exercised 3 times a week with no misses even during the fast. My workouts were not good, but after the fast, I felt really good in the gym.

    I figure I should lose another pound or two during the second round of Prolon. I was able to keep on my calorie restricted diet until last week without feeling hunger. I hope after another fast, my appetite might go back to where it was when I didn’t feel hungry on 1200-calories a day.

    I just had blood tests, and I’m in perfect health so want to keep it that way. I’m 59 years old. I plan to do it the third time as recommended.

    I was 30 pounds overweight. Now I am 20 pounds. The diet seems to have helped me to stay on the calorie restriction path until I lose the rest of the weight.

  • Very Impressed
    Tracy (Verified Purchase)

    I am on day 3, and so far very impressed with ProLon. I have been drinking half of the L-drink and the tea in the morning and waiting until noon to start with the breakfast bar, This has really helped me stay out of the hunger zone ! I feel great so far, but very sleepy toward the early evening. I only bought one fast, but plan on getting two more to do in the next few months. I am surprised at how good the food is. So far, I’ve really liked everything .

  • Cheaper alternative
    Laurena Werner (Verified Purchase)

    The macro nutrients and some details are in the book called “The Longevity Diet” by Dr. Valter Longo. You can prepare the food yourself, but it is challenging since it is a very low protein diet. Dr. Longo’s more recent research has added the glycerin/glycerol to the diet, but he does not mention it in the original book. I did two cycles of the diet and lost 4 pounds, then 3 pounds. Do not attempt it more than once in a month. You have to drink a lot of water. Also, if you can’t eat soy you can’t use the packaged food and have to prepare it yourself. I actually found some really good vegan soup recipes, which are more satisfying than the packaged food. They needed a little tweaking to fit into the diet. The myFitnessPal app was a great help. My spouse tried the packaged food at his doctor’s insistence, and under his doctor’s supervision, and he had to eat in the middle of the night because his sugar got too low. His sugar got too low. So next month I will cook for him and see how he does. We just need to find the glycerol.

  • Great success
    Mary (Verified Purchase)

    It is excellent for biologic reboot. Two days after taking prolon, his triglycerides were normal (numbers were 300- 1000), blog sugar normal, blood pressure down, and cholesterol normal. 👍🏼👍🏼👍🏼

    Marcia K Kasper

    Is it gluten free?

    • Sasha

      According to their website “ProLon® Fasting Mimicking Diet is Lactose and Gluten Free. Individuals with allergies to nuts, soy or tomato should avoid consuming the current version of ProLon®.”

  • It's a fabulous program!
    Dee Mahon (Verified Purchase)

    It was great! I thoroughly recommend this program for anyone new to fasting and thinking they may faint or die if they dont eat for a few days. This program stops you feeling hungry and makes it much easier to ‘fast’ for a week. After that, you may choose to repeat the program a few times, or be brave enough to try a water and herb tea fast for a few days so you can feel the benefits and ‘reset’ your body and appetite whenever needed. Fasting is the great health breakthrough you’ve been looking for and this is the best possible introduction to how to do it successfully.

  • Annie delouya

    Where can I buy the crackers?

    • Taylor Izzo

      Hi Annie,

      ProLon can be purchased through their Official Site.

  • No happy with way product was delivered

    My product came damaged and was treated rudely when I called to resolve issue and was told they could not find me in the system and yet they were calling me to see how things were going and sending me emails to check in

  • weight

    soooo; once you use the prolon; does the weight come back when you stop using it?

    • Angelica (Editor)


      As stated on their website, its a short-term weight loss solution, not long-term.

      • Kelley

        I am on the third cycle of the FMD. Most of The weight does stay off if you are eating a healthy diet. I lose about 5 real pounds per cycle. I gain about 1.5 pounds per month but it may be muscle as I am now working out. So my weight loss has been over 10 pounds per 9 weeks. It targets belly fat! I have been unable to lose weight by any means before this. I eat a healthy diet but am post-menopausal. The energy and health benefits are amazing.

  • Tina

    Can I do this on Antidepressants?

    • Sasha

      hi Tina, we suggest consulting with your doctor before taking any products that may conflict with medications you are taking.

  • Marcia

    I ended up cancelling the order altogether.

  • Allergen
    Shemeka Frazier

    Seems like a great plan but if you have a nut allergy forget it.

  • Vidya nathan (Verified Purchase)

    The idea is interesting but it has salt folks who are salt sensitive may benefit from low salt diet it would be great if they had a low salt version

  • Just completed a three month cycle summer 2017
    Joanne Coghlan (Verified Purchase)

    I tried the Prolon diet July, August and September 2017. This is a challenging diet BUT think about it, you can go back to your normal diet after each five day course. For me that is a huge positive. I found that after each diet cycle I didn’t go back to my normal diet….for a period of time I made even better food choices. I learned about what true hunger meant and that I could survive it. I drank water, water, water. At the end of the third cycle my body felt much lighter, especially my abdominal area and thighs ! I have not weighed myself because for me it is not about that scale (I’m slightly overweight but have muscle from years of yoga) it is about getting better in tune with my mind and body. If you want a journey and are willing to commit go for it !

    • MW

      How expensive?

      • rmh

        $249 for 5 day supply. Seems that some people use the diet once per month so that could get expensive quickly. I am just about to embark on my first 5 days so I can say nothing about efficacy.

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