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Last updated: Nov. 8, 2017

70 Slim-Fast Consumer Reviews and Complaints

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Verified Reviewer
Original review: Nov. 8, 2017

Wow, whenever I've "stumble" upon a great, weight loss or appetite control snack over the years, I've always noticed they were foods by Slim-Fast. Currently, I'm addicted to their barbecue flavored potato chips which are much better than the high fat content ones sold at the grocery stores. I eat at least one small, 100 calorie bag of these a day. They are absolutely delicious, addictive and a great mid-day snack to hold me over until dinnertime. I miss their chocolate covered, peanut butter crunch bars so much; I can't find them anywhere. I think they got rid of them last year, because I found hundreds of boxes of them at the 99 cent store nearby.

I bought 30 boxes and went back for more a few months later when I'd finished them. I do NOT tire of these snack and those chocolate, peanut butter bars tasted exactly like Butterfinger candy bars which were my favorite treat as a kid. Slim-Fast also has these great little candy balls that look like mini-malted milk balls except that they're pretzel pieces overlaid with chocolate. Yum... I don't mind their shakes although some people on this site are criticizing their taste. Maybe that's because I always put my chilled shake drink in a blender along with ice cubes and fresh fruit. Those "smoothies" are tasty and to die for; they satisfy my hunger throughout the day and are very filling. I'll be really bummed if Slim-Fast ever goes out of business. They've got a loyal, dedicated (and trim!) fan for life!

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Verified Reviewer
Original review: Nov. 7, 2017

I have been using Slimfast (Royal Choc) for 5 years now and drink them primarily as my go to morning breakfast shake. These new shakes taste completely horrendous compared to the originals. Just awful... What have you done?! I will no longer buy the shakes due to the new taste and will miss my routine. What’s more, the new packaging is poorly made and the bottles continually break out of the flimsy cardboard containers... Too much trouble. The former twist tops were much more convenient and these new sealed tops are NOT. So disappointed.

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Verified Reviewer
Original review: Oct. 17, 2017

Last summer I had a problem wanting to vomit after drinking cappuccino. I continued to vomit almost daily after eating. I started to drink it again and once again I heaved. Went online to see if this happens to anyone else. I was shocked I was not the only person. I just bought a number of bottles online since I can't find that flavor in the stores. I will not drink them again.

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Verified Reviewer Verified Buyer
Original review: Oct. 8, 2017

First, WHY would you EVER mix this with water??? Of COURSE it's going to taste and feel terrible! Yuck! I have used Slim-Fast for probably 10 years and up until the recent packaging/flavor changes, I've loved it. Why must these companies change things?? The new bottle packaging is now mostly white. I put them in the fridge and they look like little bottles of milk - and you haven't LIVED until you have accidentally, in a rush, poured a bottle of Rich Chocolate Royale into a tuna noodle casserole!!! Stop messing things up Slim-Fast. You were just fine the way you were.

Verified Reviewer
Original review: Oct. 2, 2017

I've been buying the 2 of the four packs of the original, chocolate variety for quite some time. Although they do have the box of 8, I found it more convenient carrying two items instead of one larger box. I'm starting my review with the packaging because when the packaging recently changed, so did the flavor & even consistency. The old packaging had a twist off cap, without any need to peel off anything before opening, then a foil seal. The "new" packaging has a perforated plastic seal that needs to be removed before twisting the cap off. No big deal really... Until I actually tasted one of the new ones. It was watery & gritty and just didn't taste good. I thought maybe I just hadn't shaken it well enough so the next day, I shook extra. NOPE, same gritty, watery, bad tasting stuff. Slim-Fast has been part of my morning routine for quite some time. I'm sad to say I won't be buying it any longer. Undo whatever was recently done, PLEASE!

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Verified Reviewer Verified Buyer
Original review: Sept. 16, 2017

I've been drinking one bottle of Slim-Fast Cappuccino Delight for two or three years, and before that the milk chocolate flavored drink. I really liked these drinks, but about a month ago when I opened a bottle, the drink smelled rotten. I checked the other three bottles of the four-pack and they also smelled rotten. I figured out that probably because I had had them in my kitchen cabinet for a couple of weeks, they must have spoiled. So after that I put the drinks in the refrigerator as soon as I brought them home from the supermarket.

For a month or so, everything was fine. But this morning, I opened a drink, and there was that some rotten smell. I opened the other three bottles, and they also smelled rotten. I've read the other reviews, and concluded that something has been going on with the way the drink is being prepared. Considering that the company is obviously very well aware of this, I would be very happy to participate in either a complaint to the FDA or a class action lawsuit.

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Verified Reviewer
Original review: June 12, 2017

Slim-Fast curbs sweets cravings. It used to make me feel a little sick (years ago when I used it). About a month or two ago I started using again. Not every day. Now I can better handle empty stomach too. I have lost weight with Slimfast exercise/ active. No pop. Good to hear good comments and to know side-effects. Good way to lower blood pressure. Need to lose 50 #. Eat a lot of nuts, fruits/veggies and eggs every day.

Verified Reviewer
Original review: June 5, 2017

I have been using Slim-Fast for over a year and have managed easily to take 20 lbs off and keep it off. I freeze the shakes, like them better that way, and use the plan 3 times a week. I originally decided to try it because it has been around for so long that I thought it must work for someone. I saw so many negative comments that I decided to obtain an account and write a review. I love it!

Verified Reviewer
Original review: April 27, 2017

I ran into a lady in Walmart and saw that she had Slim-Fast in buggy and asked what she thought about it. She says that she has lost weight drinking it but was dieting too, so she has changed her eating habits a bit. She mostly bragged on curbing the appetite. I was all in then. I bought a big box because I will try about anything once. I bought the 4 hr hunger control. Does it work? Doesn't work on me, I still am hungry. I bought creamy chocolate. Does it taste good? If you like the smell of moth balls, that is the sense. I don't mind the protein texture, which some may describe as chalked.

I understand that, but the taste... whoosh! I would rather drink a flavored whey protein drink or Svelte called hello beautiful which is an organic protein shake also sold at Walmart. The cappuccino is awesome, and the taste is unmatched. Good luck if you like Slim-Fast and their new flavor. I had tried it before and didn't remember it tasting so bad. They may need to rethink it and bring back the flavor that worked. Why are companies always wanting to change things were. They were just fine before. :)

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Verified Reviewer
Original review: April 4, 2017

It has been over 8 years since I last used Slim-Fast drinks in my daily diet. My busy schedule and now turning 52, I have packed on a few extra pounds, more likely over 20 lbs. Thank God I remembered what helped me in my past. I turned back to the drinks that were formerly in a can, now in a great plastic bottle. I freeze them overnight and by lunch time they are perfectly thawed into a deliciously cold drink. I have IBS and was afraid that it may trigger problems, but fortunately they haven't bothered me one bit. They help take the cravings for the sweets I crave so often far away and fill me enough so when I go home I desire a healthy dinner. I am on my third week of using Slim-Fast again and have noticed a huge difference on how I look and feel. My wife also enjoys the results I have received. I use the Cappuccino, the Milk Chocolate and the Dark Chocolate. I love all three flavors. Dark being my favorite.

Verified Reviewer
Original review: March 19, 2017

I am writing because I have only one complaint about your product. I canNOT open the container very easily. I have attempted several different ways, but to very little avail. Also, due to this situation, I can never "grab and go" with Slim Fast. In this world of hurry, hurry, hurry I would love to have a SlimFast to drink in my car as a snack or whatever. I love the creamy-milk chocolate and drink it daily.

Verified Reviewer
Original review: Jan. 13, 2017

I have been using Slim-Fast creamy milk chocolate for years and love it UNTIL you changed it and the new one "milk chocolate" is undrinkable. Taste very bad. Are you ever going to change it back? Before the change when I needed to lose a few pounds it worked very good. I only have a return receipt because I always buy 2 8-packs and could only return 1 that was unopened.

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Verified Reviewer
Original review: Jan. 3, 2017

I tried all the products, bars, shakes etc. I got so sick I had to go to the hospital. I was hospitalized for gastrointestinal issues. The Doctors told me to stop using Slim-Fast and that was what was making me sick.

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Verified Reviewer
Original review: Dec. 17, 2016

Slim-Fast - it sure tastes good if you like being nausea for the whole day. I got the powder and mixed it with water. It was fine before but this is my third can and only the second time of drinking a shake out of this one and as it says above so sick for the day. I've been on this diet for a little over 2 weeks. I've never had this problem with my pre-mixed drink. Oh well it must be just like Pedigree I fed my three dogs that almost died and that was all they ate no snacks and they had seizures and bloody diarrhea but they don't poison things. BS.

Verified Reviewer
Original review: Dec. 4, 2016

Ive been drinking SlimFast shakes for a couple of months now. Not to lose weight by using them as a meal replacement, but more so to lose weight by adding more protein to my diet. I have yet to find a protein drink that I like. However, I tried the high protein shakes and actually think theyre pretty good. I prefer the creamy chocolate which reminds me of liquid pudding really. There is an aftertaste, but it's not unbearable... and still tastes much better than protein powders in my opinion.

I did experience some cramping in the beginning, but it is my understanding that it is because I was taking in more fiber which my body was not used to. I do not have any cramping issues at this time. The cramping was very mild anyway, so it wouldnt have been the worst thing if it did continue. My overall opinion is I think they are a good alternative to protein powders. They taste pretty good, theyre filling because of the content - many nutrients! And they help you lose weight! Sounds great!

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Verified Reviewer
Original review: Nov. 11, 2016

Have had a long relationship with Slim-Fast. Easy for a busy woman. Often wished I could buy them at the airport before a flight. However, I am not happy with so called new and improved Slim-Fast. Do not like the taste... much too sweet and they have reduced size in the packaging (I buy at Sam's) and the price doesn't reflect the lessened quantity. Now I've purchased Kellogg's protein shake... will see how that works.

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Verified Reviewer
Original review: Sept. 9, 2016

I love Slimfast, I lost over 30 lbs after my second child. Simply had one for breakfast then a snack like a piece of fruit or a Slimfast bar. I had a larger lunch and a snack, then dinner I would have another shake that I would put in the blender with a banana and/or espresso to make a frozen smoothie. I normally drink chocolate. Those of you who have stomach cramps, the reason why is the fiber. If you are not getting enough fiber in your daily diet then add fiber suddenly, normally you will have gas or cramping 'til your digestive system gets used to it. Ok face it... for those of you who are afraid of the thickening added to Slimfast. Everything we eat has something in it. You won't be on Slimfast forever if you stick to a good diet. Once you have lost your weight you can stop drinking Slimfast and maybe add an Ensure or Boost to your daily replacement meal drink. I love Slimfast!

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Verified Reviewer
Original review: Aug. 14, 2016

I honestly don't know why so many reviewers are having issues with the Slim-Fast advanced nutrition. All of the products are delicious and keep me feeling full. I will agree with the one review that the coffee shake makes my urine smell like coffee for a day. Other than that I love this product.

Verified Reviewer
Original review: Aug. 1, 2016

I bought a box of 4 hour control caramel Almond Hunger control bars. Nasty stuff. The almond stinks. Old almond. It makes you throw up. I guess Slim Fast wants people to lose weight by getting sick eating their products. Shame on Slim Fast. First I thought maybe the bars have expired date on it and Wal Mart is selling them not knowing is outdated but when I read on the packaging it had another 5 months before it expired.

Verified Reviewer
Original review: July 16, 2016

I have been asked by my physician to lose weight before surgery. I had decided to try the SlimFast Protein Drink. I had been advised to watch for all products that add "CARRAGEENAN" to their products for thickening. CARRAGEENAN has very bad reviews and can lead to cancer. So to my dismay, when I was ready to buy SlimFast for a diet routine, I noticed that "CARRAGEENAN" was in their shakes. I immediately decided against this product. I am so disappointed that the makers of SlimFast decided to use CARRAGEENAN in their products. Now let me also tell people that there are a lot of dairy products and other types of products (pizza crust) that have CARRAGEENAN in them. People need to be aware of this & watch for it. Myself and others have written to some of the companies (ex: Almond Milk) and they have removed this product. SLIMFAST think of the livelihood of your customers. Listen to what we say.

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Verified Reviewer
Original review: July 2, 2016

I've been heavy most of my life and I've never been a great dieter. I decided to switch it up and try some meal replacement shakes. I went with Slim-Fast. Used unsweetened vanilla soy and the Chocolate Royale powder, blended it with ice, so it was exactly like drinking a choc milk shake. I started on January 7th and replaced 2 meals a day, a balanced dinner with little to no exercise. The most I did was a 30 minute walk to and from my daughter's school. To date, I have lost 70 lbs. I couldn't be more excited. Start weight was a whoopin 209 lbs and I am currently 140 lbs. I would definitely recommend this (and have) to my friends and family. Great product and has changed my life forever.

Verified Reviewer
Original review: May 26, 2016

I am 37 years old and have recently decided to get serious about my weight loss. I anticipate a most challenging journey with a goal of losing 100 pounds. I was enthusiastic about eating one balanced meal and substituting the other two with Royal Chocolate Slim-Fast. I did this faithfully for 2 weeks. At first, I felt great. I used unsweetened almond milk to make the shakes. They were enjoyable and satisfying. However, at the end of the two weeks, I had only lost four pounds which is ok, but it should've been more with such a drastic caloric intake shift. I also included exercise in my daily routine.

The deal breaker for me was my face. I started getting large pimples on my face like I have not had in years. My skin has always been pretty clear throughout adulthood. I'm deducing that all the sugar and chocolate wrecked my complexion. Prior to purchase, I was aware of the chemical content and the reviews expressing concern over the unhealthy ingredients in Slim-Fast, but I still wanted to give it a try. I did, and now I'm moving on to something else.

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Verified Reviewer
Original review: May 7, 2016

I have been a regular Slim-Fast user for almost 15 years. My daily breakfast would consist of a Slim-Fast and an oatmeal breakfast bar. It was a very convenient way for me to eat breakfast in the morning. It was never about using it as a weight loss drink, it was about starting my day with a nutritious breakfast. When I went to the store to pick up more this week I saw that you had changed your drinks. I would buy the Chocolatey Royale. Your new drink is called Creamy Chocolate. And you cut down from 8 bottles to 4 bottles.

Fine, I can live with that. But when I tried your new drink while driving to work I had to pull the car over because I thought I was going to vomit. I couldn't believe how horrible this new drink tasted. I thought maybe I didn't shake the drink enough before I drank it. But no, even after shaking it my Slim-Fast was possibly the most vile thing I have ever tasted in my life. I poured the rest of my drink onto the street and drove to work very disappointed.

I really don't know what I'm going to do about my breakfast. I have been driving from store to store to see if they had any old Slim-Fast remaining and I have about enough to get through to the end of the month. I cannot stress how HORRIBLE and DISGUSTING your new drinks are. I am hoping that with enough negative feedback you might go back to the old Slim-Fast. Maybe you will need to suck it up like Coca-Cola did and bring back Classic Slim-Fast. You probably won't but I will try to remain as optimistic as possible. Yours truly, a very disappointed ex-Slim-Fast user.

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Verified Reviewer
Original review: May 2, 2016

I bought Slim-Fast power 4 days ago. The first time that I drank it at night, it gave me really bad stomach cramps and gases. I was thinking could be the milk and I decided to use only water in the second time. In this case was worse, the stomached was really painful. I wake up with cramps at 4 o clock in the morning and I felt like throwing up everything... I will throw away the rest of it. This is a really bad product.

Verified Reviewer
Original review: April 8, 2016

I started taking the SlimFast shakes about two month ago. I've lost about 15-20 pounds. For me it works. When I first started drinking the shake I notice that sometimes I would get really bad stomach pain in the mornings. Then I notice that it was only when I would drink the bottle that said high protein on it. So I switch it around. I would take a regular one for breakfast and a high protein one for lunch. It's been working like a charm. No complaints at all. I order all my shakes online, that way I have all the flavors and can switch them up.

Original review: Feb. 19, 2016

I drank Slim-Fast when I was overweight as a younger person. Never had any complaints. Now I started to drink it for a week. Lost 3 lbs but it gave me really bad cramps in my stomach and gas that was extremely painful. I will throw away the rest that is left and not drink anymore. Everybody's different. You might not get this pain or symptoms. I'm very unhappy. Advice try one package before you buy a month's worth.

Verified Reviewer
Original review: Jan. 23, 2016

I have been drinking Slimfast shakes (ready to drink) for over 25 years and now without even letting people know they change it and decide to add Stevia as a sweetener. Well I didn't know this but noticed my stomach was really bothering me after drinking which it never did before. I called them and after sidetracking they finally said they added Stevia (doesn't say this on bottle). Then I researched Stevia and find it causes digestive discomfort in many people and is hard on the stomach. Slimfast what are you thinking why would you do this!! I will now be changing to something else for breakfast as I cannot drink these shakes anymore.

Original review: Nov. 5, 2015

I am disappointed in the new size and limited choice of the snack bars. I have substituted Danon Light yogurt with chocolate on top and find them much more satisfying. I still use the shakes but limited choice of flavors is a big turn off.

Verified Reviewer
Original review: Sept. 1, 2015

I buy two boxes a week and I agree with some of the other reviews that sometimes the bars are smaller. Sometimes wider and or so hard you can't bite into them. I can handle the smaller and wider bars. I want fresh product. It's the hard as a rock bars that brought me to this site and I am tired of paying so much for bars I can't eat. :/ Fix it!

Verified Reviewer
Original review: Aug. 30, 2015

Was about to get on this plan again, but based on these negative experiences, decided against it. Thank you all for sharing. Hope the company improves the product. The rating I gave is for the time I used this product which was 29 years ago and I remember achieving decent results - not stellar but a decent start to weight loss which had to be coupled with rigorous exercise. I looked at it more like a detox program. The only thing I did not like at the time was that there was not much variety in SlimFast's products to choose from.

Slim-Fast expert review by JJ Virgin

Slim-Fast carries a line of nutrient-enriched bars, snacks, pre-packaged meals, protein powders, and dietary supplements. However, it is most known for its canned shakes that work as meal replacements. Slim-Fast uses a "3-2-1" diet plan to help you remember your daily dietary requirements: each day on the program you can consume three 100-calorie snacks; two 200-calorie meal replacement products including shakes, smoothies or meal bars; and one 500-calorie dinner of your choice.

  • Simplification: Slim Fast direct consumers to eat three snacks, two bars or shakes, and one sensible dinner--the 3-2-1 program. Many dieters appreciate this simple plan. Because this diet sticks to a defined amount of calories per day, most customers will see fat loss within the first month.

  • Planning: Slim-Fast's “My Daily Plan” chart allows you to customize day-by-day what foods you will eat. Planning is key to successful fat loss, and Slim-Fast will appeal to anyone who wants a super-simple fat loss plan.

  • Convenience: Slim-Fast is accessible and convenient. Unlike other plans that require you to pre-order meals, you can find Slim-Fast products in most grocery stores and drugstores. Slim-Fast is for anyone who needs fast, on-the-go, readily available shakes and bars as meal replacements.

  • Emphasis on calories: Slim-Fast is a low-calorie diet, which is why it succeeds for some people. For athletes and other very active people who demand a nutrient-rich, higher-calorie diet, Slim-Fast is simply too low in calories.

  • Ingredients: Some of the ingredients might not be preferable for everyone, especially if you want to avoid sugar and stick with natural, minimally processed foods. With its emphasis on calories, Slim-Fast neglects quality ingredients and nutrients as vital components of healthy fat loss.

  • Best for: teens, college students, busy adults, dieters on a budget, older men and older women.

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JJ Virgin

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Celebrity Nutrition & Fitness Expert JJ Virgin is author of New York Times bestseller “The Virgin Diet: Drop 7 Foods, Lose 7 Pounds, Just 7 Days.” She is also the best-selling author of “Six Weeks to Sleeveless and Sexy” as well as a prominent TV and print media personality.

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