Ozempic linked to increased risk of blindness

Ozempic and Wegovi, which contain the glucagon-like peptide 1 receptor agonist (GLP-1RA) semaglutide, continue to be blockbuster drugs for Danish pharmaceutical giant Novo Nordisk. The company's overall sales doubled year-over-year to a whopping $1.35 billion in 2024, according to a Forbes report.¹

These options may seem convenient, but the obsession with weight loss “magic bullets” may be doing more harm than good, according to published research² Semaglutide has been shown to increase the risk of serious gastrointestinal side effects. Recent studies have shown that this drug may also put vision at risk.

Ozempic may increase the risk of blindness

In a retrospective study³ In a study published July 3, 2024, in JAMA Ophthalmology, researchers suggested an association between semaglutide intake and nonarteritic anterior ischemic optic neuropathy (NAION) among participants with type 2 diabetes and/or who were obese and overweight.

To give you some context, NAION is a condition in which blood flow to the optic nerve, the nerve pathway that connects the eye to the brain, is cut off. When blood flow is cut off, blindness (which is painless) can occur suddenly. According to Brightman and Women's Hospital, NAION “causes significant loss of vision in one eye upon awakening in the morning,” and once it occurs, the vision loss is stable.⁴

In the JAMA Ophthalmology study, the authors selected papers involving a total of 16,827 participants from December 1, 2017, to November 30, 2023. In this group, 710 people were diagnosed with type 2 diabetes, and 194 of them were prescribed semaglutide. In addition, 979 people were overweight or obese, and 361 of them were prescribed semaglutide.⁵

After accounting for covariates such as sex, age, systemic hypertension, and hyperlipidemia, the researchers determined the cumulative frequency of NAION in the population. Results showed that 17 NAION events occurred in the type 2 diabetes subgroup. Twenty NAION events were recorded in the overweight/obese subgroup.⁶

The analysis using the model to calculate the risk of developing NAION showed surprising results. Semaglutide can significantly increase the risk of developing NAION compared to other existing drugs for diabetes and obesity. According to the researchers, using the drug increases the risk of developing NAION by 4.28 times if you have diabetes and by 7.64 times if you are overweight/obese.⁷

However, it should be noted that this study was an observational study. The researchers stated that “future studies are needed to assess causality,” and did not address the specifics of how semaglutide might lead to NAION. However, the study still has merit. All cases of NAION treated with semaglutide were reviewed by experienced neuro-ophthalmologists. To their knowledge, this is the first study to look at the association between semaglutide and NAION.⁸

A detailed investigation into the association between semaglutide and retinopathy

While the JAMA Ophthalmology study is the first to examine the link between semaglutide and NAION, it is not the first time that other researchers have found a link between semaglutide and eye damage, particularly in the context of diabetic neuropathy.

For example, a study in 2023⁹ According to a paper published in Diabetologia, during the trial phase of semaglutide (2016), the drug was observed to increase the risk of retinopathy, especially in those who already had diabetes. Another study¹⁰ Semaglutide has been shown to be associated with a significantly higher incidence of retinopathy complications, including blindness and vitreous hemorrhage.

What factors contribute to this complication? According to a study published in the World Journal of Diabetes, uncontrolled type 2 diabetes may be a contributing factor when taking semaglutide. Specifically, the duration of diabetes was longer, the initial HbA1c in the blood was higher, and the insulin treatment rate was higher at the start of the trial.¹¹ Simply put, if you have chronic diabetes, taking Ozempic may significantly increase your risk of retinopathy.

Interestingly, this study highlights the important role of gut health in diabetes management and how a healthy gut may help reduce the risk of diabetic retinopathy.¹²

“Gut dysbiosis, i.e. chronic imbalance within diverse microbial communities, appears to be associated with several inflammatory/metabolic diseases and central nervous system (CNS) disorders, particularly retinopathy, an expression of a new concept called the 'microbiota-retina axis.'

Indeed, since chronic diabetes is associated not only with retinopathy but also with severe gut microbiota dysbiosis, the associated changes in the bacterial community may drive the development of retinopathy via their effects on the lipid content of retinal and CNS tissues… “

Inhibiting the GLP-1 receptor may have other side effects.

Taking GLP-1RAs Could Be Harmful to Your Health: 2021 Study¹³ According to a study published in the Journal of Investigative Medicine, these drugs may increase the risk of gastroparesis, a condition that slows or stops the movement of food from the stomach to the small intestine.

This study presents two patients. The first is a 52-year-old woman with well-controlled diabetes. She came to the researcher's clinic for upper abdominal pain after a meal, characterized by fullness, bloating, and nausea. After tracing her medical history, it was discovered that she had been taking semaglutide injections for a month before the onset of symptoms.¹⁴

After testing, semaglutide was found to delay stomach emptying. As a result, the drug was stopped for 6 weeks, and another round of testing showed that stomach emptying had improved.¹⁵

The second patient was a 57-year-old woman with similar symptoms. She had had type 2 diabetes for 16 years and had been taking weekly injections of dulaglutide (another GLP-1RA) for 15 months. Tests showed that the drug delayed stomach emptying, and gastric motility normalized when the injections were stopped.¹⁶

In another study,¹⁷ A paper published in JAMA noted that in addition to stomach paralysis, GLP-1RAs may also increase the risk of biliary tract disease, pancreatitis, and intestinal obstruction. EudraVigilance, a system of European medical organizations that monitors adverse drug reactions, also noted metabolic, nutritional, urinary, cardiac, and eye disorders associated with semaglutide.¹⁸

Other published studies have linked GLP-1RAs to the development of pancreatic cancer.¹⁹ Acute kidney injury.²⁰ In rodent studies, Wegovy has been shown to induce thyroid C-cell tumors at doses similar to those used in humans, and is contraindicated in patients with a history of medullary thyroid cancer.²¹ Additionally, the Wegovy product label warns users about the following side effects:²²

Boost your GLP-1 receptors with polyphenol-rich foods

Back to the role of the gut microbiome, increasing GLP-1 expression instead of suppressing it may be more beneficial for weight loss. One way to do this is to colonize the gut with Akkermansia muciniphila, a type of bacteria that naturally secretes the GLP-1-induced protein. The researchers noted in a study published in the journal Nature Microbiology:

“A. muciniphila increases thermogenesis and glucagon-like peptide-1 (GLP-1) secretion in high-fat diet (HFD)-induced C57BL/6J mice by inducing uncoupling protein 1 and systemic GLP-1 secretion from brown adipose tissue.”

The importance of Akkermansia in supporting gut health cannot be overemphasized. In my interview with Georgi Dinkov, I explained why Akkermansia is such a key species. However, many people are deficient in this particular microbe, which I believe is due to a lack of energy production, which in turn causes oxygen to leak into the gut.

Certain foods, especially those rich in polyphenols, may promote the growth of Akkermansia in the gut and support overall health. Healthy sources include berries, broccoli, apples, ginger, onions, green tea, and carrots.²³ research²⁴ A paper published in the International Journal of Molecular Science explains how Akkermansia is linked to better health.

“Ackermansia muciniphila is a mucosal commensal that is considered a marker of the gut microbiota in healthy individuals, but its relative abundance is markedly reduced in subjects with intestinal inflammation and metabolic disorders.

Dietary polyphenols significantly stimulate the relative abundance of A. muciniphila, contributing to the alleviation of several diseases including obesity, type 2 diabetes, inflammatory bowel disease, and liver damage.”

Nature already has its own Ozempic

Berberine, a natural compound found in goldenseal, burdock, Oregon grape, and tree turmeric, has been nicknamed “nature’s ozempic” for its ability to naturally aid weight loss.²⁵ According to a study published in Molecules,²⁶ Its properties may help manage type 2 diabetes, obesity, atherosclerosis, cancer, and cardiovascular complications. Researchers explain how these benefits occur.

“It positively contributes to increasing fasting, postprandial blood glucose and glycated hemoglobin levels while reducing insulin resistance. It improves insulin secretion by stimulating glycolysis and inhibits gluconeogenesis and lipogenesis in the liver. Berberine also improves ovulation by reducing insulin resistance.

Berberine's anti-obesity action is also well known. Berberine acts as an anti-sclerotic agent, lowering LDL and testosterone levels. This alkaloid exhibits anti-inflammatory properties by inhibiting the expression of cyclooxygenase 2 (COX-2) and prostaglandin E2.”

These findings have been confirmed in other published studies. One systematic review found that berberine may help control blood sugar levels and improve insulin sensitivity.²⁷ This is an important factor because insulin resistance is closely linked to weight gain and obesity, and addressing it can improve insulin sensitivity and, consequently, weight loss.²⁸

Another study²⁹ According to a paper published in Frontiers in Cellular and Infection Microbiology, berberine “may help alleviate the pathological state of metabolic disorders, and the mechanism is related to the regulation of the gut microbiota.” In addition, berberine's ability to modulate the gut microbiota may promote absorption.

Minimize your linoleic acid intake for better long-term results

I believe that the elusive weight loss magic bullet the world is chasing will not exist in our lifetime. As the evidence shows, relying on drugs that alter the body's essential functions can lead to worse health problems. And if you stop taking Ozempic/Wegovy, you are likely to regain the weight you lost. According to the report,³⁰ Most people who stop taking semaglutide regain two-thirds of the weight they lost, a phenomenon known as the “ozempic rebound.”

For safer and healthier weight loss, it is important to address excessive intake of linoleic acid (LA), one of the biggest factors driving the current obesity epidemic. Linoleic acid is an omega-6 fat found in seed oils commonly used in cooking. Representative examples include soybean, cottonseed, sunflower, rapeseed (canola), corn, and safflower oils.³¹

In addition to avoiding foods cooked or made with these oils, ditch processed foods, fast food, and restaurant food. If you must eat out, check out the Templeton List.³² We list restaurants known for serving healthy food. We consider criteria such as locally sourced sustainable ingredients and using healthy oils in their cooking.

Finally, I recommend minimizing your LA intake to less than 5 grams per day (or even better, less than 2 grams). This is similar to what our ancestors consumed before the chronic health problems that plague modern society became widespread. For more information on the dangers of LA, read my article, “Linoleic Acid – The Most Destroying Component in Your Diet.”