Optislim vs Optifast: Discover Which Works Better

by Claire Huffman
Last Updated: 21/03/2020
This post may contain affiliate links. We receive a small commission at no cost to you when you make a purchase using our link. Learn more.

You started your diet on Monday, but tomorrow is Thursday and you already feel you’ve got no more ideas for further quick meal preparations. Not to mention that you’ve got millions of tasks and chores left unticked on your monthly to-do-list… So what do you do?

You either grab a coffee and a sweet, but stocked with calories, pastry during break hours or you may consider a pick-up-and-go meal replacement that will satisfy your hunger while assisting your weight-loss plan.

If you’re one of the many busy people who are looking forward to kick-starting weight loss by reducing calories, the Optislim and Optifast weight loss programs based on meal replacement shakes might be a good choice for you.

These dietary products are sold online, through retail shops or in health stores.

In order to fit the multitude of dietary needs and preferences, the meal supplement shakes of Optislim and Optifast contain a satisfactory amount of calories in a single take, fueled up with either protein, fibre as well as vitamins and minerals.

The most recognized product of the Optislim and the Optifast programs are the meal replacement shakes which are easy to use and simple to prepare and pack. They come in a variety of flavours such as banana, mocha, salty caramel, cookies, etc. which makes them a tasty alternative to regular meals.

In other words, Optislim and Optifast weight-loss products are a healthy, portable convenient choice for a diet on the go. Even more, they may prevent any temptation over fast food during high levels of hunger and also keep you satiable for several hours.

Though based on meal replacement shakes, Optislim and Optifast are weight loss programs that differ in many aspects. Buyers might notice an evident competition between these two brands when considering to implement them in their weight loss plan.

Each program has advantages and disadvantages, so it is advisable to inform yourself first before making a final choice and purchasing the products.

Here is a comparative overview of the Optislim and Optifast programs:

What is Optislim?

Optislim chocolate

Optislim is a top-rated Australian wellness program that is designed for rapid loss of excess weight.

It is designed to support the process of weight loss and weight management by providing a Very Low-Calorie Diet (VLCD) and Low-Calorie Diet (LCD) meal replacements in a range of shakes, soups, and bars full of essential vitamins and minerals.

The Optislim VLCD Meal Replacement Shakes may provide the daily recommended intake of 25 vitamins and minerals when consumed three times a day. Each box contains 21 sachets with a flavour of either vanilla, banana, coffee, chocolate or strawberry.

Optislim is a cost-effective way that will provide you with a steady weight loss. All food replacements come in different flavours or in assorted packages.

Optislim’s most recognized products are VLCD Meal Replacement Shakes, Healthy Option meals, weight loss capsules, and detox products.

Each product is a nutritionally balanced but low in calories and fat.

What is Optifast?


Optifast is a regimented program for rapid weight loss that includes shakes for weight loss that may replace 1 to 3 regular meals, according to an individual lifestyle plan.

The Optifast is a VLCD Program, meaning a very-low-calorie diet for severely overweight and obese people but also for people who want to speed up their weight loss through a ketogenic, i.e. low-carbohydrate diet.

The main highlights of the Optifast program are the Optifast VLCD Protein shakes in different flavours as well as the desserts, soups, and bars that provide satiety and maintain lean muscles while the body is in a state of ketosis-meaning it burns fat for energy instead of carbohydrates.

Despite the low-calorie diet, Optifast contains the essential amount of vitamins and minerals as well as protein, fatty acids, and carbohydrates that provide rapid loss of weight but balanced body functions.

The Optifast program is divided into four levels: Active Weight Loss Level, Intensive Level, and Maintainance level. Each stage has Optifast shakes, snacks, desserts, soups and bars that ought to provide the necessary daily intake of vitamins and minerals and trace elements.

The Active Weight Loss Level 1 is compromised of twelve to sixteen weeks of total meal replacement with the Optifast products. Fast-forward to the Transition Level of four to six weeks of slow returning to prepared meals and lastly, the Maintainance phase which balances the use of meal preparations and prepared meals.

The Optifast VLCD Intensive level included allows you to enter and proceed with mild ketosis by replacing up to 3 meals per day with the dietary products offered in the weight loss program.

The products also follow the Codex Alimentarius International Standards for VLCD/VLED.

Moreover, Optisfast is a medically supervised program with the support of health professionals who help their clients through monitoring, counselling, and classes, aiming toward a healthy lifestyle with positive eating habits and balanced weight.

Optislim vs Optifast

If you are in doubt about whether you should choose Optifast or Optislim for your diet based on a meal replacement plan, you should initially consider the cost-effectiveness of both of these programs as well their results in terms of weight loss and the possible long-term maintenance of the effects.

Both Optifast and Optislim are similar because they offer meal replacement products with essential nutritional value. However, Optislim limits its offer to meal replacements that promote weight loss whereas Optifast offers a medically supervised program.

Having in mind that calorie-restricted diets may harm a person’s health if taken without medical consultation and assessment, Optifast may be a preferable weight loss program due to the higher level of safety provided by the monitoring and assistance of health professionals included.

On the other hand, however, the Optislim Meal Replacement Shake is more cost-effective as the product contains 21 sachets vs 18 sachets of the Optifast Meal Replacement Shake per box.

In addition, when it comes to lifestyle and personal schedule, it can be said that Optifast may be quite a time consuming dietary solution for many since it involves monitoring, classes, reports, and counselling. If you opt for Optifast, be ready to incorporate another task in your busy routine.

If this sounds too demanding, then maybe you should consider Optislim as a more convenient dietary method. However, Optislim does not offer any support during weight loss nor step by step introduction toward weight maintenance and long-term healthy eating habits.

Although users of both Optislim and Optifast have confirmed losing weight through weight loss shakes and other dietary meal replacements included in the programs, Optifast holds an advantageous position in terms of maintenance of lost weight.

Optislim will induce weight loss through low-calorie meal replacements that provide quick results. The results may be fast achieved but hard to maintain in the long run since calorie-restricted diets are often draining and harmful to health.

The regimented program of Optifast, on the other hand, includes a maintenance phase as the last and longest phase of the program, where you would attend support sessions to consolidate your newly learned positive eating habits and thus, sustain your weight and figure.

Moreover, you can buy Optifast online at Chemist Warehouse or at clinics, hospitals and at certain doctor’s offices. You can order and purchase Optislim only in Australia through eBay or its official website.

Are They Good for Weight Loss?

Weight loss programs

Both Optislim and Optifast may make you lose weight rapidly. However, dieticians and health professionals are adamant to advise that diets with meal replacements are only a step toward your goal of losing and maintaining your ideal weight, but not a permanent solution.

The best long-term wellness results are obtained through a calorie-controlled diet and regular exercise.

If you want to lose weight through VLCD or diet loss shakes you must, above all, consult your doctor or health care provider before you decide upon taking up any fitness program or product.

Very low-calorie diets or weight loss programs based on diet shakes have a general lack of nutrition and practitioners often face exhausting hunger, fatigue and other side effects such as headaches, constipation, dry mouth, dizziness, and hair thinning.

In addition, scientific research by dieticians has shown that meal replacements, in general, cannot guarantee to provide all the necessary trace elements and nutrients that can be obtained through high-calorie meals.


Why Is Optifast More Expensive Than Optislim?

When considering Optifast vs Optisilm you may wonder why the dietary program of Optifast is a more expensive one.

The main distinguishing aspect of these programs is that although both of them offer a wide range of dietary products, Optifast is also a medically supervised program that offers three stages of dieting and weight management between 26 and 52 weeks, followed and monitored by health professionals.

Optislim is a weight loss program that is mainly focused on rapid loss shakes but it does not include medical assistance during the process of weight loss nor professional dietary counselling that may help you maintain balanced, healthy body weight and positive eating habits.

Are Optifast and Optislim Gluten Free?

All the OptiFast VLCD products contain a certain level of lactose and soy-based ingredients. Potential consumers with Coeliac Disease or gluten intolerance should have in mind that the OptiFast VLCD Chocolate, Cappuccino Flavour & Berry Crunch Flavour Bars are made of ingredients that contain processed oats. So, although these bars are not made with ingredients that contain gluten, they may still be unsuitable for the gluten- intolerant.

OptiFast shakes, desserts, and soups are similarly made of ingredients containing egg. Optifast Bars are also products that may contain pine nuts and peanuts.

Although Optislim is not a brand that offers a variety of gluten-free products, its OptiSlim VLCD Platinum Plus Meal Replacement Shake is a gluten-free friendly weight-loss shake, and one of the few suitable gluten-free options from this brand. Moreover, this is one of the rapid loss shakes that contain only natural colours and flavours and a mix of prebiotics and probiotics.

The Bottom Line

Losing excess body weight through diet shakes and dietary meal replacements may be a practical solution when you want to get rid of extra pounds and fat in a quick way.

Both Optifast and Optislim are convenient dietary programs that offer portable, nutritional meals that can provide a long-term diet regime on the go.

These programs offer effective weight loss plans in the shortest plausible time-frame of 2- 6 weeks. However, Optifast may be considered as a rather preferable choice for consumers due to its medically supervised plan and counselling during the process of losing weight.

Though Optislim is also an effective program, it is focused solely on meal replacements in the range of shakes, bars, and soups. For some people, Optislim may be a better option since it does not include diligent counselling, monitoring or classes.

Regardless of your personal choice when you opt for one of these dietary programs, you should always keep in mind that before starting off any of the VLCD diets, you should consult your doctor or health care professional in order to secure your safety and wellbeing.

Finally, VLCD and LCD programs and methods may help you to make the first step toward fighting obesity or excess body weight. When supported by assisting medical guidance, VLCD and LCD programs focused on meal supplements can be an effective and healthy way of losing weight.

However, the old golden rule of healthy, nutritional and balanced meals accompanied by regular exercise remains to be the best long-term solution to ideal body weight and figure.

Recommended Product


16 thoughts on “Optislim vs Optifast: Discover Which Works Better”

  1. just to let you know – you can purchase Optislim at Chemist Warehouse and always have been able to, I did so today and have done so previously, and they DO also offer a gluten free soup.

    • Hi Amy, I’m not aware there are any issues but you should speak to your GP first as each individual situation is different.

    • Hi Claire thanks for your article, wanted to share that I have used Optifast with success. Once you get past the first 48 Hours cravings for food and salty/sugary snacks is minimal.
      I’m not much of an over-eater and often skip meals, but I am a complete sugar addict. Whatever the balance is in Optifast it just stops the urge to binge on sugar in its tracks. The shake flavours are pretty good especially the chai and feel like a treat rather than a meal replacement. I also like the cranberry cereal bar as a textural change. You also consume 2-4 cups of non starchy veg across the day. I’ve bought a couple of single serves of optislim to see if the $$$ savings are worth the change, but haven’t been swayed. (I haven’t tried anything from the optislim VLCD platinum though). I’ve also tried the meal replacement shake from Aldi, which were tasty, inexpensive but comparatively they are loaded with sugar.
      If you shop around you can usually pick up Optifast for under $3.50 a serve and under $3 if you’re really lucky. My income relatively low but I don’t find optifast unaffordable.

      Whatever works 🙂

    • Hi Michelle, you could try. Just note that you may not be able to tell which one is working/not working for you.

  2. I’m 72, and obese. I would like to try either OptiSlim or OptiFast to get a kick start to losing weight. Would you recommend for me?

    • Hi Maggie, I can’t recommend one because each individual situation is different. You should speak to your GP or someone who helps you look after your health to determine what the best option is for you personally.

  3. Hi. I’ve been drinking optifast shakes once a day as a meal replacement but eat healthy throughout the day. I’m not following their diet to the exact no am I under any supervision. So just for a meal replacement am I better off just doing Optislim

    • Hi Tess, if what you are doing currently is working for you, then there is probably no point in switching. If not, then you could consider trying Optislim.


Leave a comment