Sweet’N Low does not raise blood sugar in any meaningful way, making it a functional sugar substitute for people with diabetes. Its active ingredient, saccharin, has zero calories and no direct glycemic effect. But the full picture is more nuanced than a simple “yes, it’s fine,” especially if you use it heavily or rely on it as a cornerstone of your diabetes management.
How Sweet’N Low Affects Blood Sugar
Saccharin, the sweetener in Sweet’N Low, does not trigger a significant insulin or blood sugar response. In a crossover trial comparing saccharin, sugar, and plain water in healthy men, saccharin produced insulin levels nearly identical to water. At the 60-minute mark, insulin after sugar was roughly 50% higher than after saccharin. While saccharin did show a slight, late rise in insulin between 120 and 180 minutes, it wasn’t statistically significant. The researchers concluded that saccharin had no glycemic effect.
This is the main reason diabetes organizations have historically considered saccharin an acceptable alternative to sugar. Swapping a teaspoon of sugar (about 4 grams of carbohydrate) for a packet of Sweet’N Low removes those carbs from your meal without sacrificing sweetness.
What’s Actually in the Packet
Sweet’N Low isn’t pure saccharin. The first ingredient listed is dextrose, a simple sugar used as a bulking agent so the packet has enough volume to pour. It also contains cream of tartar and calcium silicate (an anti-caking agent). The amount of dextrose per packet is small enough that the product rounds to zero calories and less than one gram of carbohydrate under FDA labeling rules. One or two packets in your coffee won’t register on your glucose monitor, but if you’re using ten or more packets a day, those trace carbohydrates can quietly add up.
The Gut Microbiome Concern
The more complex question is what saccharin does beyond the moment it hits your bloodstream. A well-known 2022 study published in Cell found that two weeks of saccharin consumption, even at doses below the official safety limit, altered the gut microbiome in healthy volunteers. Some participants developed impaired glucose tolerance, meaning their bodies handled sugar less efficiently after the saccharin exposure period. Not everyone was affected equally. Researchers classified volunteers as “responders” (those whose glucose handling worsened) and “non-responders” (those who showed no change).
To confirm the microbiome was driving this effect, the team transplanted stool from both groups into germ-free mice. Only the mice receiving stool from “responders” developed the same glucose impairment, establishing a causal link between the microbiome changes and worsened blood sugar control. Sucralose (Splenda) showed a similar pattern, while aspartame and stevia did not produce the same glucose-related microbiome shifts.
This doesn’t mean Sweet’N Low will make your diabetes worse. It means that for some people, regular saccharin use could subtly undermine glucose tolerance over time. If you’re using it occasionally, this is unlikely to matter. If you’re consuming multiple packets daily for months or years, it’s worth paying attention to whether your blood sugar trends shift.
How Much Is Considered Safe
The FDA sets the acceptable daily intake for saccharin at 15 milligrams per kilogram of body weight. For a 150-pound person, that works out to roughly 1,020 milligrams per day. Each Sweet’N Low packet contains about 36 milligrams of saccharin, so you’d need to use around 28 packets daily to hit that ceiling. Most people use far less. The safety limit exists with a wide margin, and staying well below it is easy with typical use.
If you’ve heard concerns about saccharin and bladder cancer, those stem from older rat studies that used extremely high doses. The mechanism that caused tumors in rats doesn’t apply to human biology. Saccharin was listed as a possible human carcinogen in 1981 but removed from that list in 2000 after human studies found no clear association with bladder cancer.
How It Compares to Other Options
Sweet’N Low is one of several zero-calorie sweeteners available, and each behaves a bit differently in the body.
- Stevia did not produce the same microbiome-driven glucose impairment that saccharin did in the Cell study, which may make it a better long-term choice for heavy daily use.
- Sucralose (Splenda) showed microbiome effects similar to saccharin, with some participants developing impaired glucose responses.
- Aspartame (Equal) did not cause glucose-related microbiome changes in the same study, though it carries its own set of debates around other health outcomes.
No artificial sweetener is a magic bullet for diabetes management. The Mayo Clinic notes that eating artificially sweetened foods instead of sugary ones may not be as beneficial as once assumed, particularly for people who consume large amounts regularly. One reason: sweeteners can maintain your preference for intensely sweet flavors, making it harder to reduce overall sugar cravings.
Practical Takeaways for Daily Use
For most people with diabetes, using a packet or two of Sweet’N Low in coffee or tea is a reasonable, low-risk swap that avoids the blood sugar spike of sugar. It becomes less straightforward when consumption is heavy and sustained over long periods, where the microbiome research raises legitimate questions about glucose tolerance effects that vary from person to person.
If you rely on Sweet’N Low daily and notice your blood sugar becoming harder to manage over time, consider rotating between sweetener types or reducing overall use. Tracking your glucose response before and after periods of heavier artificial sweetener consumption can give you personalized data that matters more than any population-level study. The simplest approach is to use it in moderation and treat it as a tool for reducing sugar intake, not a replacement for broader dietary choices that keep blood sugar stable.