10 Costco Kirkland Products With Questionable Ingredients

You can generally rely on Costco's products to be made with pretty good ingredients. Although the retailer isn't quite in the same camp as other supermarkets, like Sprouts Farmers Market and Trader Joe's, when it comes to claims about the types of things it avoids in its foods, it generally keeps things pretty considerate. Its items generally feel pretty good quality, and the nutrition of its foods isn't bad in most cases.

However, that isn't always the case. As with virtually any other retailer, Costco has some items with ingredients that may well raise some eyebrows — and they may well be items that you should leave on the shelf. Additives like erythritol, maltodextrin, and carrageenan can be found in its products, and even some of its most famous items (like its rotisserie chicken) contain components you might not expect. Elsewhere, Costco opts for controversial ingredients like palm oil and yellow 6 in some of its goods, which you may well miss if you're not looking closely. We're sorry to tell you, but you may well be better off avoiding some of these items entirely.

Crumbled bacon can be a great ingredient to have to hand if you want to spruce up salads, pasta dishes, or baked potatoes, and it makes sense to buy it in bulk, given how quickly it can disappear (hey, it is delicious, after all). That's why Kirkland Signature Bacon Crumbles seems like a good purchase. Coming in a 1.25-pound bag, it ensures that you won't burn through your supply too rapidly, and it's been praised by customers for its full, fresh flavor.

However, the fact that these bacon crumbles have sodium nitrite in them puts us off. Nitrites are common in bacon products and cured meats, and are used to both suppress bacterial growth and preserve flavor and color. However, synthetically produced nitrites can lead to nitrosamine production, and nitrosamine formed specifically from sodium nitrite has been found to potentially increase the risk of colorectal cancer. Costco's product may taste good, but you're better off grabbing bacon without any added nitrites and making your own bacon crumbles from scratch. It'll likely be more fun, too.

Looking to get some sick gains, bro? Then you might be tempted by Costco's Kirkland Signature Protein Bars. With 20 bars per box, and each bar delivering 22 grams of protein, this product feels like a no-brainer if you're trying to build muscle mass. Plus, the fact that each portion has just five grams of sugar is also very appealing.

The way that it keeps its sugar content down, though, is something you should definitely be aware of. Kirkland Signature Protein Bars get their sugary flavor partly from erythritol, an artificial sweetener that's had a lot of negative publicity in recent years. That's because of its potential effects on cardiovascular health, which are definitely concerning. A research team partially funded by the National Institutes of Health conducted a study on erythritol and its impact on heart health, finding that people who consume it in higher quantities may have an increased risk of developing blood clots. This could then lead to an increased risk of stroke or heart attack. As erythritol has become more widespread in the last few years, its long-term effects need much more attention. It could be worth looking for protein sources without this additive in the meantime.

Who loves the cheesecake from Costco? All of you? Yeah, that's what we thought. Costco's cheesecake selection is as appealing for its flavors as it is for the mammoth size of each bake, but look a little closer at the ingredients lists and you'll see some cause for concern. Costco's Kirkland Signature New York Style Strawberry Cheesecake, for instance, contains palm oil and palm oil shortening, both in its graham cracker crumb and as an ingredient in other components. As fats go, palm oil is pretty questionable, mainly for the disastrous impact that its harvesting has had on the environment. The ramp-up of palm oil production in the last few decades has led to a huge amount of deforestation, destroying wildlife habitats and contributing to higher levels of greenhouse gases. It may be cheap and widespread, but it comes at a cost.

Costco's Kirkland Signature New York Style Strawberry Cheesecake also has some other ingredients that might raise some eyebrows. The cake has a host of gums and thickeners, like guar gum, locust bean gum, cellulose gum, and carrageenan. It also has plenty of other preservatives and additives elsewhere, and it contains a total of four allergens. This is a product that's packed to the rafters with ingredients, folks; natural, it ain't!

Costco's a great place to bulk-buy candy, and it doesn't just stick to products made for its Kirkland Signature label. It also stocks a host of candies from name-brand producers, in bumper packs that ensure that they last a while. Its Kirkland Signature Funhouse Treats variety pack is an example of this: Although it's nominally a Kirkland product, each bag contains multiple fun-size packages of Skittles, Twizzlers, Starburst, Sour Patch Kids, and Trolli, amongst others.

It probably won't surprise you, though, that these candies don't have the best ingredients in them. Virtually everything in here is full of corn syrup, sugar, palm kernel oil, modified starch, and gums. Several of the candies also contain food dyes, with the Sour Patch Kids, Lifesavers, Haribo Goldbears, Starburst, Airheads, Skittles, and Trolli candies all containing Yellow 5. 

Yellow 5 has been linked to several potential health effects, including hyperactivity in children and a possible impact on gene formation that could lead to higher cancer risk. As of April 2025, Yellow 5 and other petroleum-based synthetic dyes are being phased out of food production in the United States, but they're still present in these candies.

On the surface, Costco's Kirkland Signature Deluxe Cauliflower Crust Pizza sounds pretty good. The cauliflower crust makes it gluten-free and hints towards it being somehow healthier than other pizza (cauliflower's a veggie, after all), and the roasted vegetables on top promise a little bit of nutrition. However, its ingredients really are a sight to behold. The list of stuff in these pizzas is as long as your arm, and it's a highly processed item containing more additives and preservatives than you can shake a stick at.

There are numerous ingredients here that raise an eyebrow, with sodium nitrite, modified starch, xanthan gum, and sodium erythorbate all making an appearance. One which can be easy to miss is dextrose, a type of sugar that can have all of the effects that glucose has, and is included in the pepperoni here. Oh, and there's sugar as well, hidden in the garlic purée, which is a bit of a wild choice for what's clearly a savory ingredient. This is a classic example of a natural-seeming product being chock-full of things you might not want to be eating.

What's so bad about a humble animal cracker? Surely, these little bites don't have much going on in them — especially when it comes to Kirkland Signature Organic Animal Crackers, which by their very "organic" nature, seem to promise a sense of wholesomeness. Sadly, though, they're not quite as innocent as they seem. Kirkland Signature Organic Animal Crackers contain solely organic ingredients, but one of these is organic palm oil.

Producing palm oil organically may avoid using pesticides and other nasty chemicals, but it still impacts the environment pretty heavily, and can cause deforestation as severely as non-organic palm oil farming. Organic palm oil is the primary fat used here, too.

Kirkland Signature Organic Animal Crackers also contain "natural flavors," which may not be as wholesome as you might think. Natural flavor can be subject to a huge amount of processing and alteration before it ends up in food, and it's a mistake to think that it's necessarily better for you than artificial flavor. Natural flavors don't necessarily have a nutritional impact, but it's also hard to figure out exactly what's in them and how much they've been processed.

Look, we're sorry to ruin this for you, but those delightful cinnamon rolls you like from Costco might not be the best choice, ingredients-wise. Sure, you may not be that surprised by this, given that Kirkland Signature Gooey Cinnamon Rolls aren't exactly a healthy food, but let's break it down all the same. Cinnamon rolls are a classic treat, but Costco's are highly processed, and packed to the rafters with additives, preservatives, and texture enhancers. Dextrose, modified cornstarch, mono- and diglycerides, and various gums are all present, as well as a lot of sugar.

That's all before you get to the main ingredient: Bleached enriched flour. Bleached flour undergoes more processing than regular flour, and while strides have been taken to avoid using any additives that could cause harm, the fact is that it's treated with aggressive chemicals like chlorine to lighten it. It gives bakers a cleaner slate to work with, but it's also an ingredient that has a level of processing that we don't love. The flour gets points for being enriched, but couldn't it have just been untampered with in the first place?

We're about to break hearts with this one. Costco's rotisserie chicken is a timeless fan favorite, and while it may have pleased people's taste buds for years, it's not quite the simple product that you might expect. Kirkland Signature Rotisserie Chicken has a couple of extra ingredients in it, which are added through the saline solution injected into the meat. These add flavor and texture, but in forms that you might not love: As well as salt, this solution contains sugar, dextrose, modified food starch, and potato dextrin.

It also contains carrageenan, arguably the most controversial ingredient on the list, and one of the most controversial ingredients in recent memory. Degraded carrageenan has been observed in studies to harm the gut, with inflammation, lower bacterial diversity, and ulcer formation all observed as a result of consumption. Questions have been raised about its safety for people who have inflammatory bowel disease. It's a surprise, therefore, that Costco's chicken still contains it. It's also an ingredient that's really easy to miss — most of us just assume that those chickens just contain, well, chicken.

Costco's very good at making desserts that have a touch of class to them, and its Kirkland Signature Tuxedo Chocolate Mousse Cake fits the bill. This cake comes out of the box ready to serve at an elegant occasion, and it's perfect for weddings or birthdays. Plus, if you weren't looking closely, you'd be forgiven for thinking that it doesn't have anything odd in its ingredients: Compared to a lot of other Costco products, its ingredients list is super short, with just eight separate components making it up.

However, make sure you read until the end of its ingredients, as the last one is artificial flavors. Artificial flavors are in many things, of course, and they're generally considered safe — but it's also true that we're not aware of their long-term effects just yet. More pressingly, though, we're a little surprised that Costco would opt to use these in what's clearly meant to be a chic dessert. Could it not have opted for something a little more, y'know, organic? Plus, this cake also has ingredients like soy lecithin, and its nutritional profile isn't the best: It has a high amount of saturated fat and a lot of added sugar.

As candy goes, chocolate-covered raisins can feel somewhat more wholesome. Sure, they still have chocolate in them, but raisins are a fruit and have a lot of energy in them, and so it's basically a kinda healthy pre-workout snack, right? Well, not only is that not true because of their potential nutritional profile, but also because food manufacturers can add all sorts of ingredients that you might not like. A good example of this is in Costco's Kirkland Signature Milk Chocolate Covered Raisins, a product that has corn syrup, dextrin, and maltodextrin.

This last ingredient is one that we'd really rather not see. Maltodextrin, a sweetener, has been observed to have a potentially harmful impact on the gut and could well be a risk factor for people with inflammatory bowel disease. It also may prompt gut inflammation more generally. Oh, and if that wasn't a good enough reason for you to potentially give this product a miss, its ingredients list also mentions that they were "partially produced with genetic engineering." We're not sure we're fans of that.