Pain medications can affect blood sugar, but the direction, size, and clinical importance of the effect vary enormously depending on which drug you are taking, how much, and for how long. Some pain treatments raise glucose sharply and predictably, others nudge it slightly lower, and a few barely touch it at all. Adding to the confusion, pain itself drives blood sugar up through stress hormones, which means the condition being treated is already shifting glucose levels before any pill enters the picture. Understanding the specific risks of each drug class matters most for people with diabetes or prediabetes, but the interactions are worth knowing even if your blood sugar has never been a concern.
Pain Itself Raises Blood Sugar
Before blaming any medication, it helps to know that acute pain triggers a hormonal cascade that independently raises blood glucose. In a controlled study of healthy volunteers, experimentally induced pain produced a two- to three-fold increase in cortisol, a rise in epinephrine, and elevated free fatty acids, along with increases in glucagon and growth hormone.1PubMed. Acute pain induces insulin resistance in humans These hormones collectively tell the liver to dump glucose into the bloodstream and make cells less responsive to insulin. The result is a temporary state of insulin resistance that can push glucose higher for hours or even days during a painful episode.
Psychological stress works through the same pathway. The release of catecholamines and glucocorticoids triggered by stress increases insulin requirements and promotes insulin resistance, raising blood sugar levels.2PubMed Central. Stress-Induced Diabetes: A Review For someone managing diabetes during a painful injury or recovery from surgery, this means glucose may climb even before any medication is given. A pain medication that effectively reduces pain could, in theory, lower blood sugar indirectly by dialing down the stress response.
Over-the-Counter NSAIDs
Nonsteroidal anti-inflammatory drugs like ibuprofen, naproxen, and aspirin are the most commonly reached-for pain relievers, and their relationship with blood sugar is more complicated than most people realize. At standard over-the-counter doses, the effect on glucose is small enough that most clinicians consider it negligible. A study of diabetic patients found that ibuprofen at 600 mg three times daily produced a statistically significant but modest drop in blood glucose, while ibuprofen at 300 mg three times daily produced no meaningful change at all. The researchers concluded that conventional NSAID doses should not be relied on for treating high blood sugar and that they could be used safely alongside oral diabetes medications.3PubMed Central. Effects of nonsteroidal antiinflammatory drugs in conventional dosage on glucose homeostasis in patients with diabetes
The picture gets more interesting at higher doses or with longer use. Research in a rat model of type 2 diabetes showed that ibuprofen lowered hemoglobin A1c and improved early-phase glucose tolerance, but also triggered high insulin release and ultimately contributed to insulin resistance.4PubMed Central. Effects of ibuprofen in the ZDF rat model of type 2 diabetes That dual nature, improved inflammation markers on one hand but potential metabolic strain on the other, is a theme that recurs across anti-inflammatory drugs. A recent lab study also found that ibuprofen and naproxen inhibit the sweet-taste receptor that helps the body detect glucose, and that long-term ibuprofen intake is associated with preserved metabolic function and lower risk of metabolic diseases like diabetes.5PubMed Central. Ibuprofen inhibits human sweet taste and glucose detection implicating an additional mechanism of metabolic disease risk reduction That research is still in early stages, though, and nobody should take ibuprofen as a diabetes prevention strategy.
High-Dose Aspirin Is a Special Case
Aspirin deserves its own discussion because at high doses, its glucose-lowering effect is substantial and well-documented. In patients with type 2 diabetes, high-dose aspirin therapy reduced fasting blood glucose by roughly 25%, lowered the area under the glucose curve after a meal by about 20%, cut hepatic glucose production by around 20%, and improved insulin-stimulated glucose uptake by a similar margin.6PubMed Central. Mechanism by which high-dose aspirin improves glucose metabolism in type 2 diabetes The mechanism involves aspirin’s ability to inhibit an inflammatory signaling pathway that contributes to insulin resistance. These effects were seen at doses far above what anyone would take for a headache, and the gastrointestinal and bleeding risks at those doses make high-dose aspirin impractical as a diabetes treatment. Still, it demonstrates that NSAIDs, through their anti-inflammatory action, have a real capacity to shift glucose metabolism.
Acetaminophen and Blood Sugar
Acetaminophen (the active ingredient in Tylenol) is often considered the “neutral” pain reliever for people with diabetes because it does not carry the cardiovascular and kidney risks of NSAIDs. On blood sugar itself, its direct metabolic effect in normal use appears to be minimal. Animal research suggests acetaminophen can actually protect against blood sugar problems: in mouse models, daily acetaminophen prevented and partially reversed high fasting blood glucose, and in mice on a high-fat diet it largely prevented the development of impaired glucose tolerance and excess insulin.7PubMed. Acetaminophen normalizes glucose homeostasis in mouse models for diabetes The proposed mechanism involves the drug’s ability to reduce reactive oxygen species in liver mitochondria, which could protect the insulin-producing cells in the pancreas.
There is a concerning flipside. Early-life exposure to acetaminophen in mice impaired glucose metabolism in offspring, with increased insulin levels and reduced liver glycogen content.8PubMed Central. Impact of perinatal exposure to acetaminophen on hepatocellular metabolic function in offspring And in the rare but serious event of acetaminophen overdose, severe liver damage can cause dangerous drops in blood sugar. Case reports document patients developing lactic acidosis and hypoglycemia secondary to acetaminophen-induced liver failure, a scenario where the liver simply cannot produce glucose anymore.9PubMed. Anion gap acidosis with hypoglycemia in acetaminophen toxicity At normal doses, this is not a realistic concern, but it underscores why staying within recommended limits matters.
The Acetaminophen CGM Problem
If you wear a continuous glucose monitor, acetaminophen raises a completely separate issue that has nothing to do with actual blood sugar. It can make your CGM display falsely high readings. In a pilot study, patients whose plasma glucose stayed constant at about 90 mg/dL saw their CGM readings swing wildly between roughly 85 and 400 mg/dL after taking acetaminophen, with the interference pattern tracking the drug’s concentration in the fluid under the skin.10PubMed Central. Direct Evidence of Acetaminophen Interference with Subcutaneous Glucose Sensing in Humans: A Pilot Study The electrochemical sensors in older CGM systems cannot distinguish acetaminophen from glucose, so the drug registers as sugar that is not there.
Newer CGM systems have been designed to reduce this interference. Testing of an investigational system (which became the Dexcom G6) specifically evaluated acetaminophen-associated bias after a standard 1-gram dose in people with type 1 or type 2 diabetes and found the problem was substantially improved.11PubMed Central. Resistance to Acetaminophen Interference in a Novel Continuous Glucose Monitoring System If you use a current-generation sensor, the risk of false highs from acetaminophen is much lower than it once was. But if you use an older model and take Tylenol, you could see phantom glucose spikes that might prompt unnecessary insulin corrections, a genuinely dangerous situation. Checking with a fingerstick meter before making treatment decisions is the safest approach.
Corticosteroid Injections for Pain
Corticosteroids are among the most potent glucose-raising medications in existence, and they are widely used for pain management, from epidural steroid injections for back pain to joint injections for arthritis. Even a single local injection can send blood sugar soaring. In diabetic patients receiving epidural steroid injections, mean blood glucose jumped from about 160 mg/dL before the injection to roughly 286 mg/dL afterward, an average increase of about 126 mg/dL with a half-life of just over one day, meaning patients returned to their baseline within roughly two days.12Spine. Effects of Epidural Steroid Injections on Blood Glucose Levels in Patients With Diabetes Mellitus
Shoulder injections in patients with type 2 diabetes showed a similar pattern. Mean glucose rose from 136 mg/dL before injection to 159 mg/dL during the first three days, and the time spent above 250 mg/dL roughly doubled on the first day. Four out of 25 patients experienced new glucose readings above 350 mg/dL, though these spikes were short-lived and none of the patients needed changes to their diabetes treatment.13JSES International. The effect of steroid injection into the shoulder on glycemia in patients with type 2 diabetes Smaller injections into the hand and wrist caused more modest increases, averaging around 14 mg/dL on the first day after injection.14PubMed. Effect of local corticosteroid injection of the hand and wrist on blood glucose in patients with diabetes mellitus
The general pattern is clear: the larger the steroid dose and the closer it gets to the bloodstream, the bigger the glucose spike, and the spike resolves within a few days. For most patients the effect is temporary and manageable, but if you have diabetes and a provider recommends a steroid injection, expect to monitor more closely for two to three days afterward. A conversation about your current diabetes management before the injection is worthwhile.
Opioids
The metabolic effects of opioids are surprisingly complex and often run in opposite directions depending on baseline glucose levels. A review of the literature found that the vast majority of studies report opioid stimulation raises blood glucose under normal conditions. However, in people who already have high blood sugar, such as patients with type 2 diabetes, opioid stimulation tends to lower glucose levels.15PubMed Central. The Clash of Two Epidemics: the Relationship Between Opioids and Glucose Metabolism The body also uses its own endogenous opioids as part of glucose regulation; beta-endorphin levels rise in response to low blood sugar, creating a bidirectional feedback loop.
Long-term opioid use is a different story. People on opioid maintenance therapy with methadone or buprenorphine tend to be overweight and insulin resistant, with impaired glucose metabolism, increased sugar cravings, and disrupted lipid profiles.16PubMed Central. Metabolic profiles associated with opioid use and opioid use disorder: a narrative review of the literature Comparing the two, buprenorphine-treated patients generally show better metabolic markers than methadone-treated patients, including lower rates of metabolic syndrome and better insulin sensitivity.17PubMed Central. Metabolic and Addiction Indices in Patients on Opioid Agonist Medication-Assisted Treatment: A Comparison of Buprenorphine and Methadone If you take opioids regularly for chronic pain, periodic metabolic screening is a reasonable precaution regardless of your diabetes status.
Drugs for Nerve Pain
Gabapentin, pregabalin, and duloxetine are commonly prescribed for diabetic nerve pain specifically, which means their effects on blood sugar have direct relevance for the people most likely to use them. A retrospective study comparing all three found that among patients whose pain improved substantially, those on duloxetine had significantly lower hemoglobin A1c values than those on gabapentin or pregabalin.18PubMed. Comparative analysis of the therapeutic effects of pregabalin, gabapentin, and duloxetine in diabetic peripheral neuropathy: A retrospective study That might make duloxetine sound like the metabolic winner, but the picture is more nuanced. Duloxetine itself causes modest increases in fasting blood glucose, and while A1c did not rise in short-term placebo-controlled studies, longer-term treatment showed a larger A1c increase with duloxetine than with routine care alone.19Diabetes Care. Does Treatment With Duloxetine for Neuropathic Pain Impact Glycemic Control?
Gabapentin and pregabalin work through different mechanisms and carry their own metabolic concerns, primarily weight gain. Even a modest gain of several kilograms, as documented in a small percentage of gabapentin-treated patients, can worsen insulin resistance and make blood sugar harder to control over time.20PubMed Central. Evaluation of efficacy and safety of gabapentin, duloxetine, and pregabalin in patients with painful diabetic peripheral neuropathy None of these drugs is disqualified by its metabolic effects, but the choice between them can reasonably factor in which side-effect profile fits a given patient’s metabolic situation best.
Cannabis and Blood Sugar
Medical cannabis is increasingly used for chronic pain, so its metabolic effects deserve attention. A large population-based analysis found that current marijuana users had about 16% lower fasting insulin levels and about 17% lower insulin resistance scores compared with nonusers.21PubMed. The impact of marijuana use on glucose, insulin, and insulin resistance among US adults That sounds encouraging, but the finding comes from a cross-sectional survey, which cannot prove cannabis caused the difference. People who use marijuana may differ from nonusers in dozens of ways that affect metabolism.
When researchers looked at the question more carefully in a clinical setting, following chronic pain patients who began medical cannabis treatment and measuring their metabolic profiles before and three months after starting, they found no significant change in fasting glucose, hemoglobin A1c, insulin, lipids, cortisol, or body weight.22PubMed. Metabolic effects of medical cannabis treatment The most honest read of the evidence is that medical cannabis, mainly in extract form, probably does not move blood sugar in a clinically meaningful way over a few months of use, though longer-term data are sparse.
Local Anesthetics
Lidocaine and related local anesthetics are used for everything from dental work to nerve blocks for chronic pain. At the doses used for most procedures, blood sugar effects are unlikely. But there is some evidence that higher doses of lidocaine can lower blood glucose. In patients with heart failure who received large doses of lidocaine before surgery, clinically significant hypoglycemia was observed, likely because lidocaine competes with glucose production for liver enzyme capacity.23PubMed. Hypoglycemia caused by lidocaine overdosage Lab studies have shown that lidocaine can stimulate insulin release from pancreatic cells at certain concentrations while inhibiting glucose-stimulated insulin release at higher ones.24Biochimica et Biophysica Acta (BBA) – Molecular Cell Research. Effect of tetracaine and lidocaine on insulin release in isolated mouse pancreatic islets In practice, the typical injection at the dentist’s office or for a nerve block does not deliver enough lidocaine to budge your blood sugar. This becomes a concern mainly in patients who receive prolonged or large-volume infusions, particularly if they have liver disease.
Kratom and Herbal Pain Remedies
Kratom, an herbal supplement widely used for pain relief and opioid withdrawal, has traditional uses as a blood sugar reducer. Lab analysis confirms that mitragynine, the primary active compound in kratom leaves, potently inhibits alpha-glucosidase, the enzyme that breaks down starches into glucose in the gut, and that it works synergistically with the diabetes drug acarbose in lab assays.25PubMed Central. Inhibition of α-Glucosidase and Pancreatic Lipase Properties of Mitragyna speciosa (Korth.) Havil. (Kratom) Leaves These findings are preliminary and come from lab studies, not human clinical trials. If you use kratom for pain and also take diabetes medications, the theoretical risk of an unexpected blood sugar drop is worth discussing with your provider, even though hard clinical data are lacking.
The broader lesson from herbal pain remedies is that “natural” does not mean “metabolically inert.” Turmeric, willow bark, and various other supplements marketed for pain have their own glucose-related effects, and combining them with prescription diabetes drugs without medical oversight can create unpredictable interactions. Mentioning every supplement you take, not just prescription medications, during conversations with your healthcare team is the simplest way to catch these issues before they become problems.
Liquid Formulations and Hidden Sugars
A category of blood-sugar effect that catches people off guard has nothing to do with the active ingredient at all. Liquid pain medications, cough syrups, and chewable tablets often contain sugar, high-fructose corn syrup, or other sweeteners as inactive ingredients. For someone counting carbohydrates carefully or managing type 1 diabetes with precise insulin dosing, even a tablespoon of sugary cough syrup can throw off a meal calculation. Sugar-free versions of most common OTC pain and cold products exist, and pharmacists can point you toward them. When in doubt, the drug facts label lists inactive ingredients, and anything ending in “-ose” (sucrose, dextrose, maltose) is a sugar.