Low-carb diet in a pill – a good idea?


Here’s the most interesting drug in a long time: Forxiga (dapaglipflozin – a SGLT2 inhibitor).

The interesting thing is that it’s a low-carb diet in a pill.

Forxiga is sold as a diabetes drug but comes with a side effect that will no doubt interest many: Weight loss. 


I have no financial interests in Forxiga or any other part of the pharmaceutical industry. This post was written only because the drug is interesting.


Forxiga is a new drug for type 2 diabetics that lowers blood sugar, lowers weight and lowers blood pressure.

How does it work? Forxiga blocks the reabsorption of glucose in the kidneys. This leads to the excretion of glucose – up to 70 g per day may leak out into the urine for people with diabetes (less for people with normal blood sugar).

So the result may be the same as if you had eaten 70 g less carbohydrate that day. This results in lower levels of the hormone insulin. And the effect – lower blood sugar, blood pressure and weight – is exactly what you see in studies on low-carb diets.

The decrease in long-term blood sugar (HbA1c) is significant. But, this is not the exciting part – many diabetes drugs lower the blood sugar this much. The exciting thing is that most other diabetes drugs (especially insulin) have weight gain as a side effect. Forxiga does the opposite.


Here’s the result on weight in two studies that tested Forxiga on type 2 diabetics.

In the first study all patients received the basic medication Metformin. They were then randomly divided into two groups where one group was given a placebo addition (grey line) while the other group received Forxiga (red line):


Forxiga produced an average weight loss of 6.5 lbs (3 kg), as compared to placebo.

It’s even more exciting is to compare Forxiga with other diabetes drugs that cause weight gain. One such common group is called sulfonylureas, which act through increasing the release of the fat storing hormone insulin. Elevated levels of insulin will lower blood sugar – at the price of, among other things, weight gain.

In this second study too, all participants took the basic drug Metformin. They were then randomly assigned to two groups. One group received the sulfonylurea drug Glipizide which releases insulin (grey line). The other group received Forxiga (red line):


In this comparison Forxiga on average reduced weight by 12 lbs (5 kg)!

Side effects

Unfortunately Forxiga is not free from side effects. In particular, the risk of urinary tract infections and vaginal yeast infections increases – the result of all the sugar (food for bacteria and fungi) that leak into the urine. Furthermore, you can get an increased urine production and an increase in thirst.


Despite the side effects, this is an exciting addition to the treatment of type 2 diabetes.

Many may indeed want to use it to lose weight, even without having diabetes. However, the drug isn’t approved for this use (yet). Moreover, the effect on weight for people with normal blood sugar will likely be smaller – less sugar will leak into the urine. Thus, Forxiga is presently not a diet drug.

Then, who with type 2 diabetes may benefit from Forxiga? Here’s the treatment ladder that I use, provided there is no obvious lack of insulin (so called LADA, causing otherwise unexplained weight loss).

  1. A low-carbohydrate diet, being as strict as you can. This is often enough to normalize blood sugar without medication.
  2. If necessary Metformin
  3. If necessary a GLP-1 analogue (Victoza, Byetta or Bydureon)

Forxiga should be a good alternative as step four, but as more data becomes available, it may shoot up to number 2 or 3.

The sad part is that many will be using Forxiga instead of a low-carb diet. But, then you’ll only reach part of the effect – a maximum of 70 g glucose leakage daily will of course not be enough if you’re eating 300 g carbs per day. In addition, you may experience side effects unnecessarily. Finally, in my opinion, there’s something sick and environmentally unfriendly in eating carbs unnecessarily just to pee them out.

Forxiga may, however, be a good complement to other treatments when they are not sufficient.

The most exciting? Forxiga is low-carb in a pill. And it improves both weight and blood sugar – just like the low-carb diet.

What do you think about it?

PS: Farxiga in the US

Forxiga is sold under the brand name Farxiga in the US.


Previously on drugs

How to Lose Weight: Lose Weight by Reviewing Your Medications

Previously on diabetes

How to Cure Type 2 Diabetes

More on Forxiga

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