Updated: 09/12/2017
By Summer Banks Aug 12, 2017

I’ve heard an awful lot of hype in Keto OS reviews, lately. I bet you’re asking:

“What is keto and what does Keto OS mean to me?”

Let’s see. Keto OS says it can help with focus, sleep, energy, strength, fat loss and mood. It supplies exogenous ketones. These are ketones you eat or drink, not the ones your body makes when in ketosis. It looks like you just pour the powder in up to 16 ounces of water, shake and drink – voila!


Then check out the 4 things you MUST know about Keto OS. 

Ready, set, go…

Pruvit Keto OS Readers: Click here to find out why we're giving away samples of our product, Burn HD.

What is Keto OS?

So, let’s get down to business.

Pruvit Keto OS supplement is a powdered drink offering weight-loss support.

Keto OS ingredients are:

  • MCT powder
  • beta-hydroxybutyrate
  • stevia
  • caffeine [1] 

Keto OS Max offers the same, but l-leucine, l-taurine, and a few others are added. Just one scoop or packet a day is supposed to force you into ketosis [2], so your body burns fat instead of carbs. This idea is what low-carb diets are based on.

Wait…isn’t ketosis dangerous?

Ketosis is not to be confused with ketoacidosis, a medical condition that can be life-threatening.

What about Pruvit now?

Pruvit, the makers of Keto OS, started online in 2013. You have various options to choose from on the official website including a canister of powder or prepackaged servings, which makes the Keto OS diet plan a bit easier. I like the addition of caffeine but that’s not the best part.

Let me explain. 

Keto OS Drink – “Why Do Ketones Taste Bad?”

The first issue I found with Keto OS ingredients came with a taste that was unpleasant to some. “Get this. If you’re supposed to use the Keto OS drink to lose weight, how can you if you’re put off by the taste,” asked our Research Editor.

“It tastes like 10 packets of sweet and low in one glass of water, tastes very unnatural I would rather drink dirt,” one user explains.

“No changes occurred in a week! It tastes awful and only gave me headaches,” according to a Keto OS review. [3]

Another says, “Couldn’t even drink.”

Not everyone was unhappy. Let’s look at another example:

Taste is good, added extra ice and made in blender,” said a dieter of Keto OS ingredients.

Pruvit Keto OS Customer Testimonials

Keto OS Side Effects – “Yes, According to Pruvit”

The taste wasn’t the only problem that came up. I also found reports of Pruvit Keto OS side effects. If the product pushes the user into ketosis, some adverse reactions could be attributed to what’s often called “Atkins Flu.”

Make no mistake about it. The majority of people do feel like crap for a few days.

As the body adjusts from burning carbohydrates to fats for fuel, fatigue, muscle aches and headaches are common. “Muscle aches and vomiting within 30 minutes to one hour after each ingestion ensued,” explains one person who tried the Keto OS diet plan.

“Numerous times it made me sick to stomach, unproductive and a bit wired, [4] even without the caffeine version,” a customer reports. Another user claims, “I took 1/2 a packet and 15 hours later I was still wired and jittery from it. My heart was racing.”

But you’re probably wondering, “Does everyone feel like this?” 

Nope. Some people feel good about Keto OS supplements.

“It helps keep you in ketosis, without horrid side effects,” commented a customer.

“I drink half a pack on workout days and it gives me so much energy,” stated another.

Based on our research, it takes something that doesn’t seem important, like a few muscle aches, to cut down your chances of long-term success. There’s an issue if customers don’t have great things to say about Keto OS results or Keto OS Max.

Keto OS Results – “Can This Really Be True?”

Who else wants to know if Keto OS is proven to work?

Here’s where things get interesting with the Keto OS diet plan. There are 110 calories in each serving. But, when you combine the fat, carbohydrates and protein, it only adds up to 75. Where do the rest come from?

And that’s not all.

Another problem is the fact that none of the ingredients have anything to do with starting ketosis. [5] You also have to consider the fact that there are 970mg of sodium, which is considered quite high. [6] That’s nearly 50% of your recommended daily intake.

I believe science is critical, but I couldn’t find any to back claims of Keto OS results. [7]

Also: read our Burn HD Weight-Loss Kit review »Pruvit Keto OS Ingredients

The Bottom Line – Does Keto OS Work?

Can I be totally honest with you?

I like that it contains caffeine, but I’m concerned about no research backing the claims. You have to consider the fact that no supplement can kick you right into ketosis and the price is outrageous at $85 for two weeks.

Is a kick in metabolism what you’re looking for? We suggest trying out a product that comes with scientifically tested ingredients that work to help you lose weight without any risk of harsh side effects. The price should not break the bank.

Among the best products we’ve seen this year is one called Dietspotlight Burn. After researching and studying ingredients, we chose one with four with clinical support. They’ve been shown to help improve metabolism, fight appetite and boost fat loss.

Also, the company backs the product 100%, so they’ve chosen to offer up a Special Trial Offer.

Keto OS is a ketone booster. The term "ketone" may be familiar if you've ever followed or researched a low-carb diet. When the body burns fat for fuel in place of carbohydrates that's called ketosis. There are three versions - 2.1 Charged, 2.1 Caffeine Free and 3.0 Charged.

Pruvit Keto OS Ingredients and Supplement Facts

Serving Size: 1 Packet
Serving Per Container: 30
Amount per Serving% DV
2.1 Charged**
- Beta Hydroxybutyrate**
- MCT Powder**
- Caffeine**
2.1 Caffeine Free**
- Beta Hydroxybutyrate**
- MCT Powder**
3.0 Charged**
- Beta Hydroxybutyrate**
- Amino Acid Blend**
- Inulin**
- Caffeine**

Other Ingredients: Natural flavors, potassium citrate, ascorbic acid, butyrate, malic acid, stevia

Pruvit Keto OS Side Effects:

These days, weight-loss supplements are seemingly everywhere. This doesn’t mean that natural solutions are synonymous with being side effect free. With any formula, you are running the risk of an adverse reaction, as everyone is different. Keto OS side effects are rare, but that doesn’t mean they don’t occur with some users.

Muscle Pain

Muscle pain (myalgia) is fairly common and could occur in more than one muscle at a time. Muscle aches could also happen in the ligaments, bones, and tendons. [1] This pain is often related to tension or overuse of the muscle.

What causes muscle pain?

The most common of causes are muscle trauma or injury. Overuse of a muscle can be a factor as well as stress and diet. More serious issues may cause muscle aches as well, such as fibromyalgia, Lyme disease or lupus.


Vomiting is the act of ejecting the contents of the stomach out through the mouth and nose. Vomiting is often uncomfortable, however, individuals who vomit often feel better as nausea is relieved. This should not be confused with regurgitation, which is a different symptom altogether.

What causes vomiting?

Vomiting can be caused by a viral infection in the stomach or food poisoning. [2] Concussion and migraines can be a factor in vomiting, as well as inner ear disorders or infections.

Racing Heart

Racing heart is the speeding of the heart beyond its normal rate. Fairly common after strenuous activity, if the issue occurs longer than that period it could mean a more serious medical condition.

What causes racing heart?

When the heart feels the need to work overtime to pump more oxygen-rich blood to areas of the body, it may increase in speed to keep up with demand. Numerous factors can cause increased heart rate including, caffeine intake, stress, anxiety, or low blood sugar.


Nausea is the uncomfortable feeling of queasiness in the upper abdomen with the inclination to vomit. Nausea (also known as qualm) is the body’s warning that vomiting could soon occur.

What causes nausea?

Nausea can be caused by some factors including inner ear disorders, medications, or food poisoning. Motion sickness and vertigo could cause nausea, with more serious factors being a brain tumor, heart attack, or carbon monoxide poisoning. Keto OS side effects are relatively rare, but some users have reported nausea, vomiting, and racing heart, among some others. It’s always best to speak with a physician before taking any supplements, especially if you are under the age of 18, pregnant or nursing, taking prescription medications, or have a medical condition of any kind. To state the obvious, every person responds differently when it comes to weight loss products. One that has been talked about, Dietspotlight Burn, has been clinically proven to help accelerate weight loss, undue weight-loss plateaus and ignite the metabolism.

Pruvit Keto OS Scientific Abstracts:

MCT Powder

There was a significant effect of time on fasting serum glucose concentrations (P = 0.0177), and total cholesterol concentrations (P = 0.0386), as well as diastolic blood pressure (P = 0.0413), with decreases in these variables happening over time. Two of the three participants who showed signs of metabolic syndrome at baseline did not show evidence of metabolic syndrome at the endpoint. Results and data analysis suggest MTC oil may be included in a weight-loss program with no issues of negatively affecting metabolic risk factors. There should be distinctions made in regards to chain length whenever the effects of saturated fats on metabolic risk factors come into the discussion. [1]


In this study, participants lost 5.9 +/-1.8 (SD) kg (7.0 +/- 2.1%) body weight (p < 0.001). At the start satiety was good, leptin levels were related to the participant’s caffeine consumption (p < 0.01). Those who had high amounts of caffeine consumption found their weight, fat mass, and waist circumference to be reduced more so than those who consumed less caffeine. In low caffeine consumption users, during WM, green tea still decreased weight, respiratory quotient, body fat, and waist, whereas resting energy use was increased in comparison to the placebo group (p < 0.01). During weight management, no effects of the green tea and caffeine mixture were observed in high caffeine participants. Those who consumed high quantities of caffeine had experienced weight-loss through fat oxidation and thermogenesis and with suppressed leptin in women. [2] Age-adjusted models of the trial had displayed a lower mean weight gain in the subjects who had raised their caffeine intake than in the participants who reduced their intake. The differences were insignificant: −0.43 kg (95% CI: −0.17, −0.69) in men and −0.41 kg (95% CI: −0.20, −0.62) in women. When coffee and tea consumption increased, there was notably less weight gain in the participants. In conclusion, higher amounts of caffeine intake may reduce long-term weight gain. [3]


Both groups in the study had lost around 5% of their body weight by the ninth week of trials (−5.3 ± 0.1 % versus −4.3 ± 0.4 %, p = 0.13), but the group who took inulin lost substantially more weight between nine and eighteen weeks (−2.3 ± 0.5 % versus −0.6 ± 0.4 %, p = 0.012). Participants who ingested the inulin had decreased hepatic (p = 0.02) and soleus muscle (p < 0.05) fat content at eighteen weeks. Fasting glucose greatly reduced at the ninth week only (p = 0.005), while insulin concentrations had not altered. There was a substantial rise in GLP-1 in the cellulose participants at nine and eighteen weeks (p < 0.03, p < 0.00001). Inulin may contain a two-pronged effect of risk for diabetes by promoting weight-loss, reducing intramyocellular and intrahepatocellular lipid in those who had pre-diabetes independent of weight loss. [4]

Learn More About Burn HD »
Summer Banks Dietspotlight Author
About the Author:

Summer Banks, Director of Content at Dietspotlight, has researched over 5000 weight-loss programs, pills, shakes and diet plans. Previously, she managed 15 supplement brands, worked with doctors specializing in weight loss and completed coursework in nutrition at Stanford University. full bio.

Rating: 2.8. From 242 votes.
Please wait...

Pruvit Keto OS Customers Also Bought:

Product Star Rating Effective Ingredients Sample Offer Testimonials Money-Back Guarantee
Explanation of Chart
Burn HD
Garcinia Cambogia
Caralluma Fimbriata
Raspberry Ketones

Pruvit Keto OS

What are the side effects of Keto OS?

Keto OS side effects may include a mild headache.

What is in Keto OS?

Keto OS ingredients are beta-hydroxybutyrate, ascorbic acid, caffeine and MCT powder.

How do I know if Pruvit Keto OS is right for me?

Choosing the right product is the #1 question asked by DietSpotlight readers. We recommend trying any product before buying it and know that finding a product with a sample offer is near impossible - so we created our own product, Burn HD, with scientifically backed ingredients.

Click here to get your sample of our powerful fat burner today.

Does Keto OS work?

If you are starting a keto or low-carb diet Keto OS supplies ketones that support fat burning once in ketosis. Without dietary changes, Keto OS will not cause weight-loss.

Is Keto OS safe?

We’ve heard nothing about Keto OS dangers. But, to keep Keto OS safe, follow the directions and seek medical advice if you have a medical condition.

How to use Keto OS

If you’re wondering how to take Keto OS, you dissolve one packet in 12-16 ounces of cold water. You can drink Keto OS twice daily.

Is there a Keto OS formula available without caffeine?

Yes, there is a caffeine-free version (orange flavor) of Keto OS.

Is there a money-back guarantee for Keto OS Pruvit?

Yes, there is a 90-day money-back guarantee.

Is Keto OS sugar-free?

No, each serving of Keto OS contains two grams of sugar.

How much does a bottle of Keto OS Pruvit cost?

According to the official website, the cost of Keto OS is $85 for 15 servings.

If you’re looking for a product that offers a trial option, you may want to check out Dietspotlight Burn.

Pruvit Keto OS Reviews

Leave a comment or review

Apple cider vinegar
Nicole (Verified User)

Can I take apple cider vinegar pills with keto os/max?


What do you eat while taking Keto OS?

Anything I should expect?

Any type of reaction or side effects?

Victoria (Editor)

Hi Kim! If you’re looking to kick your body into ketosis so it burns fat for fuel instead of carbohydrates, there could be some side effects for the first week or so. It’s often called the “Atkins flu” because people following that low-carb diet experience it.

Salt is a good way to stop these flu-like symptoms, but not everyone can safely increase sodium intake. Please take any health issues into consideration before adding sodium-heavy foods or drinks.

How fast does it work?
Maureen (Verified User)

my ketone test strips show an increase in ketones in my urine within hours of drinking the supplement. Doesn’t this mean it is working? Thanks so much I would love to hear your answer.

Victoria (Editor)

Hey Maureen. The body stores around 400g of carbohydrates. There’s no possible way for the body to burn through those carbohydrates in a few hours.

You’d have to eat nothing and burn 1600 calories (4 calories for each gram of carbohydrate) and even then it would take some time for ketones to show up in your urine. Another fat burning product that you might want to check out is Dietspotlight Burn.


Haven’t tried this product yet but i guess we’ll see how it goes since I don’t eat too much carbs, I don’t like bread, and I don’t drink sodas anyways…

  Love Keto OS
Anita (Verified User)

I have been on KETO OS for about 3.5 weeks now. I started out slow by only taking a half serving of the Orange Dream for about four days and then upped it to full serving a day on the fifth day. However, I only drink half in the morning and the other half in the afternoon and I do not get any sort of stomach upset. I have been following a Keto diet 65pc fats (the good ones of course), 35pc protein and 5pc carbs (which all come from veggies). My swollen ankles are now down by about 95pc, I wake up refreshed, I have energy, I don’t feel hungry and I no longer crave sugar which was my arch nemesis for SO long. I love this product (don’t love the price) but it works for me so I will continue to use it. From what I understand to get your body in ketosis naturally you have to be perfect in the 65/35/5 and if you get off of it even a little bit it will kick you out of ketosis. This product insures that you stay in ketosis and you don’t have to be so strict in your eating habits. Everybody is different, so some people will not be able to tolerate it I’m sure but for those who can, it is a God send!
I am not giving Keto OS a five star only because I wish it wasn’t so dang expensive


You’re supposed to be drinking over 100 ounces of water while on Keto OS… yes the sodium is high but that’s meant to attempt to make your body crave water, therefore pushing the sodium out of your body while burning fat in the process. I drink more water than ever before! you should try again and adjust to drinking only a half a pack in the morning and half a pack in the afternoon…. drink a huge glass before and after and continue throughout the day.


Thank you Andrea. I am going to try this.

Anita complain (Verified User)

I love the chocolate swirl charged but when I don’t have it I have less energy then I did before I started drinking them I feel tired n get headaches from not drinking them. Either u get a life supply n don’t miss a day or don’t start bc if u don’t have it u won’t feel good. And orange dream is disgusting I can’t even drink it


I’ve tried the Orange Keto OS and i use to get real sick within half hour my friend told me to try the Chocolate one as i don’t have a gall bladder. To my surprise absolutely no stomach pains today. Fingers crossed it stays that way.

  I like it
Theresa (Verified User)

Love this product.. down 25 lbs since beginning the Keto-os .. increased exercise daily, decreased sugar, carbs, and all flour products. Combination of diet, exercise & Pruvit = success! 🙂

Not that bad
Davina (Verified User)

I love the orange one! Mix it 16oz water and ice and its good. Idk if the taste used to be bad but they’ve fixed it and the taste is good.
Also its recommended u start with half a packet because some ppl could be sensitive to the MCT.
I swear by this product. I feel great, I’ve started a ketogenic diet now on 3 wks, losing weight and inches and I’ve never felt better.

Worked for me
Kirstyn (Verified User)

I have been taking Keto from Pruvit for 10 days and I swear by it. I also changed my diet to a Paleo diet when I started it. I have lost about a pound a day and my starting weight was only 130lbs. I believe no product you take without changing your diet will give you a miracle like many hope.


Have you been drinking one or two per day? Do you split it during the day?

I wish it was cheaper
Janalea (Verified User)

Been using Keto os since March of 2016 and love it!!! The only thing is the price, it is high but the product works for me.


How much weight have you lost since then?

Not sure if it works
Duane (Verified User)

I’ve been taking Keto os daily for past 3 months. No side effects after 1-3 days initial poop fest. I have not lost any belly fat. Really not that excited about the product anymore.

Might not work for everyone
April (Verified User)

My husband started Keto in Feb. 2016 right before we were going to London. The way you are supposed to eat on the diet was really easy for him to stay on. he could order a hamburger and eat the meat, cheese, avocado, lettuce, tomato, and any other veggies. just no sugar and no complex carbs. in the first 3 months he lost 15 lbs. He does the charged in the morning and noncharged around 4. The afternoon one helps him not snack till dinner time. He has breakfast 7:30, lunch 11:00, 2nd lunch 2:00, and diner 630. He has never had any stomach problems or the jitters. Now in October he has lost another 7 lbs and still losing. I dont think it is right for everyone but it sure works for him.


The thing I don’t think people understand is that the keto diet alone WILL make you lose weight if you stick to it, and it’s likely that’s the only thing your husband is losing from. If this powder works as a placebo affect to keep him on the diet, more power to him. But if people are told to start a keto diet with this powder, it’s a giant waste of money. Just do the keto diet and save yourself some $$.


First of, her husband is eating too often to be on a true keto diet and in ketosis. I eat twice or 3 times per day and i have energy all day and am fine with it. I use Keto OS as breakfast on most days and sometimes drink 1-2 hours before afternoon workout. There is no placebo effect. It works. It’s not a waste of money, it actually will help you save money because it reduces cravings, gives satiety, and much more, plus using it as breakfast replaces the meal and a normal mid morning snack, so it’s not a strain on your wallet. I would suggest trying it first before coming to conclusions for someone else without your own anecdotal evidence.

jenni Forrester

I can not use it as a meal replacement. If I don’t eat I feel terrible!!!! I didn’t know it was ok as a meal replacement.


When I’m following a keto diet (with zero supplements) I eat 2-3 small meals a day, zero snacking, and have tons of energy. On a true keto diet you are eating to fuel your body, not for pleasure. I also lost 30 lbs in 2 months. Save your money and just follow the diet strictly. Why so end money on something that your body can make on its own naturally?

It's ok I guess
Wendy (Verified User)

First time user this morning. Tested keto stix before use and not in fat burning mode..drank keto os…didn’t taste vile at all it actually tasted ok, tested one hour later and keto stix colour was in fat burning mode and I have been testing on and off prior to using keto os and the only way it went into the other colours is if I absolutely deprived myself of carbs for weeks..give me a keto os anytime over starving

Sick sick sick

I can’t do it. The first day I was nauseated like no other. The next day I took it I threw up. Glad I got a 5 day trial.

ulcers on throat
Sarah Cox (Verified User)

i have ulcers in my mouth and in back of my throat after drinking this for a week?
COuld this be causing ulcers in mouth?


I don’t have ulcers but after I started the raspberry lemonade my entire mouth is so sore I can’t eat if I wanted to. Hence the weight loss. I am certain that was it because after just one day going back to the orange cream it started to feel better. Then I go back to it and again my mouth was sore.



Victoria (Editor)

Hi. Please make sure to consult with your physician before continuing to take this product and let them know about the side effects you were experiencing.

No thanks

I have been using this product for 4 days now. I’m a healthy person who works out 5 days a week and I have no energy. I drink 170 ounces of water a day if not more, I follow the diet recommended and I am not seeing any results. Before starting I was losing 2 pounds a week on a 1200 calorie diet with working out alone. I will be going back to this. This product has given me diarrhea, the shakes, I’m dizzy and exhausted not to mention completely bloated. This is not. Good product. Not recommended


I just cancelled my autoship. Have had diarrhea every day since starting use of Keto OS and haven’t seen any of the benefits touted on the packaging – no increased focus, no weight loss, no energy. Nothing. Very disappointed since my doctor recommended I try this.

Jo dean

I tried for 3 days. Day 3 my stomach was messed up. Might not be the right product for me


Whenever you change your”diet” or nutrition your body reacts. That’s not a bad sign. Also depends on which flavor you took, orange has mct oil, which, if you’re not used to, can give you loose stool. All of this subsides in a few days. You also need to drink electrolytes and water during the day.


I have been on it for 9 days now. There are certain packets that will upset my stomach, which is why I was given all of the packets to try in a sample packet first. But this isn’t because of KETO OS. There are some things that I can’t take or drink that have something in it that cause the same upset stomach as the flavors that I tried in KETO OS. Once I found one that worked I was ready to purchase for the rest of the month.


Its the MCT oil that is doing all the work. It depends if they are using the cheaper Capric acid in the formula whether it can upset your stomach. I had a lot of trouble in the beginning until I changed to Mercola’s which has only Caprylic Acid much easier on my tummy at least. I have been having the ‘Bullet proof’ coffee which is a tablespoon of MCT and grass fed ghee in the morning. Its a great pick me up and my little bulge has gone completely flat. Mercola also recommends not staying in a Keto diet continually. But once you have changed to fat burning mode cycle a couple of days a week of higher carbs. If you wan’t to know more I would google what he says. Its the way to go though.


Only been using a week, but I can say… Not Atkins Flu, No sickness or nauseated feeling. Try mixing in a little MiO “Tangerrine Orange flavor. Disgusies/hides the saltly taste in KETO//OS

I think this will only help Jump Start your low carb plan but don’t expect anything too be a miracle as stated above. There is nothing that works and keeps weight off more than daily exercise (2-3 days week 1 hr. Each min.)

But this with a committed Low Car PLan over 3-6 months will drop weight for folks that don’t exercise though the results won’t be a great.

Good luck to all using this.


I agree with you. This is becoming a nightmare for me. I ordered chocolate cream and got orange. I ordered to-go packs and got the jugs. Contacting the company is impossible. I’m using it with little or no results for 2 weeks.

Thomas Voelker (Verified User)

After reaching weight and A1c goals can you stop taking Keto OS ?

  Keto works
Emily (Verified User)

So I did keto os with a keto diet. One side effect from eating low carb, high fat, moderate protein is sometimes you find it hard to poop. I usually try and add more veggies. I find keto os can still work if you eat anywhere under 100g carbs a day. Cause I’ve been eating banana.. that’s 30g and this desert which is 27g plus a nippy milk drink which I think is about 30g carbs aswell. The first week I lost 5kg.. but I stopped after the first week. Just started doing it again but not so over powering. I’ve lost 1kg in about 1-3 days. I suggest just taking keto os slow you do not want to lose to much weight at once. Once I run out of powder I’m going to do mostly keto diet.. but add in some healthy carbs like banana and sweet potato. And more veggies for fibre. I try to go to the gym everyday to burn atleast 300 calories and I try to keep busy all day. Basically all my weight loss is from keto os.. since July 25 it’s not 15 sept I’ve lost atleast a total of 6 kg. I stifle have about 15kg to go..