Is Sucralose (Splenda) Vegan? And Is It Safe?

When you’re trying to lose weight, artificial sweeteners like Splenda can seem like the holy grail. You can eat sweets and… they just don’t have calories? Amazing! But from a vegan perspective, there’s more to consider. Today, I’m taking a deep dive into everything sucralose.

Is sucralose vegan? Vegans don’t agree about sucralose (a.k.a. Splenda). Most say sucralose is vegan because it’s synthetically made and doesn’t contain animal products. However, it was extensively tested on animals, causing over 12,000 animal deaths before being approved by the FDA. And some vegans have safety concerns with sucralose, too.

Below, I’ll cover all of these issues from a vegan perspective: Should we boycott sucralose because of animal testing done in the past? And is sucralose even safe? I’ll also suggest a better, healthier artificial sweetener at the end!

Sucralose Does Not Contain Animal Ingredients

A sucralose molecule.

It’s pretty simple to see that sucralose doesn’t contain animal products. Sucralose is a very similar molecule to sucrose (table sugar). In fact, sugar is one of the starting materials when making sucralose.

In order to make sucralose, three of the hydrogen-oxygen (hydroxyl) groups on a sucrose molecule are replaced with chlorine atoms. This results in a molecule that is very sweet (600 times sweeter than sugar), but which our body mostly doesn’t break down.

Usually, sucralose comes in a package along with dextrose and/or maltodextrin. Fortunately, both of these filler ingredients are derived from corn starch and are confirmed vegan.

For many vegans, the fact that sucralose doesn’t contain animal ingredients means that it is vegan by definition. However, other vegans disagree due to the animal testing that went into developing sucralose.

Is the Sugar That’s Used to Make Sucralose Filtered with Bone Char?

If you know a lot about sugar production, you’ll know that it is sometimes filtered (decolored) using animal bone char. This is an issue that some vegans care about and others ignore, considering it a minor issue.

Since sugar is used as a starting ingredient to make sucralose, this could be a concern when determining whether sucralose is vegan.

Based on the best evidence I could find, the sugar used to make Splenda is not filtered with animal bone char. The carbon filtration is carried out with a coal-derived filter instead. Therefore, it seems to be completely free of animal use.

12,000+ Animals Died to Test the Safety of Splenda

A monkey confined for animal testing. (This image was not from testing Splenda specifically.)

When you look up information on how sucralose was tested on animals, you don’t just find one or two animal tests… you find that thousands of animals, including dogs and monkeys, died to test this product.

Some of the tests are particularly heartbreaking to read about. In one, 32 Beagle dogs lived in metal cages and had sucralose mixed into their food for a full year. They were then killed and bled out to have their organs examined for damage.

In another test, 12 monkeys were made to eat sucralose for seven weeks. After seven days, two of the monkeys were dead from brain damage. After the study concluded, the monkeys still alive were euthanized.

Here is the original article in Food and Chemical Toxicology that describes the Beagle study, along with other sucralose tests.

Thousands of rats, mice, and rabbits were also killed in the testing of sucralose by Johnson & Johnson over a 20 year period.

Should You Boycott All Products Tested on Animals?

All vegans decide for themselves exactly how strict they want to be when it comes to different ingredients and issues. And this definitely applies to the issue of animal testing.

If you’re “vegan” but you really just care about eating a healthy diet, not animal ethics, then obviously you’re not beholden to any standard of strictness. You may even choose to intentionally “cheat” on your vegan diet sometimes.

But if you’re an ethical vegan to help animals, you may swear off any product ever tested on animals, even if the ingredients themselves are vegan.

But the Animal Testing Happened in the Past?

Graffiti against animal testing. Photo by Tony Webster.

Most of the tests carried out to get sucralose approved for human consumption were carried out decades ago. When you buy (or use) sucralose today, are you even really “supporting” the animal testing done back then?

Honestly, this is still an issue I’m figuring out as a vegan. Where do we draw the line for boycotting products tested on animals?

I remember hearing that some vegans avoid all artificial food coloring because they’ve been tested on animals in the past. I was honestly surprised to hear that.

Part of the reality is just that animal testing is how our society currently ensures certain safety standards are met. As awareness of animal rights spreads through society, I think we’ll naturally see animal testing decrease more and more.

In fact, in September 2019, the EPA committed to drastically reducing funding for animal testing at universities and eliminating all tests on mammals by 2035. So we’re heading in the right direction.

But for now, it can be quite difficult for many people to ensure that they consume no products tested on animals. It means switching over all your household cleaning products, for example, and usually replacing them with more expensive alternatives.

Some vegans may happily choose to do that, but…

Boycotting Animal Testing Makes Veganism Less Accessible?

Requiring that all vegans boycott every single product tested on animals may be an excessive barrier to accessibility. It makes it a lot harder, and more expensive, to be vegan. And it may not make a big difference.

I do think it may be effective to send emails to companies and ask them to stop testing on animals. I think it’s productive to ask them to get certified cruelty-free. But if you just quietly stop using a product because it’s tested on animals, I don’t think they (or anyone) will notice.

Personally, I love it when I see the cruelty-free rabbit logo or “not tested on animals” on a product… I’ll almost always choose that brand. But I admittedly do not make a consistent effort to avoid everything that was tested on animals.

In the end, this is an issue for each vegan to decide.

Is Sucralose Safe and Healthy?

Despite the extensive animal testing that has been done on Splenda, it’s still not 100% clear that it’s safe and healthy for long-term human consumption.

So let’s look at some of the concerns that are still out there.

Sucralose as Migraine Headache Trigger

One of the problems that have been observed with sucralose is that it can trigger migraine headaches in some people.

It doesn’t cause migraines for everyone, obviously—but it’s a well-known issue. I found several mentions of not only this study, but also some anecdotal support from a practicing physician.

Sucralose and Insulin Resistance

In the video below, Dr. Michael Greger shares a bevy of studies on artificial sweeteners, with a focus on sucralose. The concern at the center of the discussion is its effect on the gut microbiome, which affects insulin resistance and more.

Splenda is not absorbed in the small intestine like normal sugar molecules, so it ends up in the large intestine. What does it do there Apparently, it messes with your gut bacteria, which affects your tolerance to carbs.

Interestingly, I also found discussions of artificial sweeteners causing insulin issues through a completely different mechanism. That is, the sweet taste may trigger an insulin response even without real sugar in your blood.

But coming back to the issue of gut bacteria…

Inflammatory Bowel Disease (IBD) and Irritable Bowel Syndrome (IBS)

As mentioned in the Nutrition Facts video above, there’s a startling pattern when you look at graphs of when sucralose was introduced in a country— a sharp increase in IBD consistently followed.

One of the papers Dr. Greger cites, from the journal Science, notes how this is an issue that patients with IBD and IBS may want to know about!

Of course, the data is based on correlations over populations, so it’s not solid evidence. That said, increases in the rates of IBD are significant, doubling in Canada for example. And the protective measure is an easy one to take: Just stop consuming artificial sweeteners and see if it helps.

Sucralose and Weight Control

The main reason people consume sucralose and other artificial sweeteners is to lose weight. But the evidence suggests that sucralose has a small impact on bodyweight.

One explanation of this: Artificial sweeteners still keep you accustomed to sweet foods. So you still get cravings for sweets, and you’ll probably end up eating more calories from somewhere.

This meta-analysis looked at a bunch of observational studies along with a bunch of randomized controlled trials (RCTs). What did it find?

• From the observational studies, it looked like artificial sweeteners had no significant impact on body mass or fat mass, while being associated with a bit higher body mass index (BMI).

From the randomized controlled trials, which generally provide better evidence, artificial sweeteners led to about 1.7 pounds of weight loss on average.

This data suggests artificial sweeteners may help aid with modest weight loss, but nothing too dramatic. (Most people would not visually notice 1.7 pounds of weight loss.)

Healthy (Vegan) Alternatives to Sucralose

So, are there any healthy artificial sweeteners? Or at least ones that seem to be harm-less?

I always liked this video (below) by Dr. Greger reviewing 8 artificial sweeteners and quickly mentioning which health issues have been associated with them. It’s a good quick overview of what to watch out for.

More ideas for sweetening food in a healthy way can be found in my “18 Healthy Ways to Sweeten Oatmeal” post. I busted out a whole bunch of creative ideas in that post. But when it comes to artificial sweeteners specifically…

The Best Artificial Sweetener: Erythritol

The clear winner, from the data I’ve seen, is erythritol. Naturally found in grapes and pears, you can also buy it to sweeten your own foods at home.

Erythritol is absorbed in your small intestine, so it doesn’t cause problems in your large intestine like other artificial sweeteners seem to. It doesn’t cause cavities, and it works well for baking.

There is even some exciting research showing that erythritol has antioxidant properties. This means that it may actually be beneficial to consume it, not just neutral.

I found erythritol in a health food store once, but if you’d rather not search the aisles for it, here’s where you can buy it on Amazon.


Here are the takeaways for vegans looking at sucralose:

It doesn’t contain animal products, so yes, it’s vegan in that most narrow sense.

It was tested on over 12,000 animals, including dogs and monkeys, causing pain and death to many of them.

It’s suspected (but not confirmed) to contribute to several health issues, including migraines, insulin resistance, and inflammatory bowel disease.

For the healthiest artificial sweetener, take a look at erythritol.

As a vegan and a health-conscious person in general, I’m personally okay with eating sucralose on occasion or in smaller amounts, but I would not make it a prominent part of my diet.

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