GLP-1 receptor agonist medications, such as Ozempic, Wegovy, and Mounjaro, have revolutionized weight loss and blood sugar control, but their widespread use has brought forth a complex range of effects, including psychological impacts, safety concerns regarding counterfeit products, and emerging health risks, alongside discussions about their long-term efficacy and cost.

These medications are not merely digestive aids; they are considered "brain drugs" due to their action on the reward center (hypothalamus), which influences mood and personality. While most users report positive psychological changes like elevated mood, increased libido, and clearer thinking due to stabilized blood sugar and reduced brain inflammation, a small minority (less than one percent) experience negative shifts. These include decreased enthusiasm and drive, anhedonia (lack of interest in pleasurable activities), irritability, or feeling subdued and "boring." Doctors attribute these to the over-suppression of pleasure pathways in the brain. If such side effects occur, medical professionals advise discussing them for potential dosage adjustments or switching to different GLP-1s, like tirzepatide, which may have less mood impact.

A critical and dangerous issue is the proliferation of counterfeit weight loss drugs. Health officials have issued urgent warnings following severe incidents, such as an influencer nearly dying after injecting a fake Ozempic purchased via social media. These illicit products often contain harmful substances like insulin, leading to life-threatening symptoms such as extreme fatigue, vomiting, diarrhea, blurred vision, heart palpitations, seizures, and hypoglycemic shock. Legitimate GLP-1 medications are prescription-only and must be obtained from registered pharmacies under medical supervision. The UK law strictly prohibits the sale and promotion of these drugs without a prescription, with offenders facing significant penalties. The booming demand for genuine drugs, which often outstrips supply, fuels this black market, making vigilance crucial for patients.

Emerging research also links GLP-1 medications to a "modestly increased risk" of sight-threatening eye conditions, particularly in people with type 2 diabetes. Studies, though some acknowledge potential confounding factors, have found an association with diabetic retinopathy (damage to retinal blood vessels) and non-arteritic anterior ischemic optic neuropathy (NAION), a rare but serious condition causing sudden vision loss due to reduced blood flow to the optic nerve. While the overall risk is considered low, experts advise regular eye checks for diabetic patients on these medications. It is important to note that current research has not definitively proven causation, only a link.

For those using weekly injectable GLP-1s, experts suggest an optimal injection day might maximize benefits. For example, taking the injection on a Thursday could help control weekend caloric urges, as stronger effects are often felt shortly after the dose. Administering the injection before a rest day can also provide a buffer to manage initial side effects, which tend to ease over time. However, patient information leaflets generally advise injecting once a week on the same day for stable medication levels.

Recent price hikes, notably Mounjaro's wholesale price more than doubling in the UK private market (e.g., from £122 to £330 for the highest dose), have caused significant concern among private users. With approximately 1.5 million people on weight loss drugs in the UK, a large portion of whom pay privately, many face affordability issues and the risk of weight regain if forced to stop. Experts advise patients considering a switch to cheaper alternatives like Wegovy to do so under strict medical supervision. Direct dose conversion is not possible, and a healthcare professional will guide the transition, often recommending a one-week gap between the last Mounjaro dose and the first Wegovy injection to avoid a "hunger rebound." Patients are strongly warned against "microdosing" or purchasing from unregulated sources due to serious health risks.

A significant challenge with GLP-1 medications is weight regain after cessation. These drugs are not a quick fix; studies show users often regain nearly half the lost weight within eight weeks of stopping treatment. This phenomenon, known as "weight cycling," is attributed to adverse hormonal changes in the gut that increase hunger, and a lack of developed behavioral strategies while on the medication. Healthcare guidelines, such as those from NICE, often recommend limiting use to two years, emphasizing that sustained weight management requires long-term lifestyle changes.

In response to the demand and side effects of injectables, new alternatives are emerging. British scientists have developed Elcella, a "natural Mounjaro" pill, containing linseed oil, coconut oil, and MCT oil. This twice-daily capsule, available without prescription, uses a special coating to release its ingredients in the colon, triggering the natural release of appetite-reducing gut hormones like GLP-1 and peptide YY. Clinical trials have shown an average weight loss of 1 stone 1 pound in 12 weeks with no reported side effects, contrasting with the common gastrointestinal issues of injectables. Elcella's creators emphasize that it promotes the body's natural processes rather than replacing hormones, leading to no dependency and additional benefits such as improved gut health, healthier hair and nails, and regular bowel movements.