Serena Williams made headlines this week when she publicly shared that she lost roughly 31 pounds after using a GLP-1 class medication as part of a health plan she described as aimed at reducing knee pain, improving mobility and lowering her longer-term metabolic risk. Her candid account — and the fact that she has worked with a telehealth provider that distributes GLP-1 therapies — has reignited public interest and debate about these drugs, which are becoming a common tool for medically supervised weight loss.
Below we break down what GLP-1 medications are, how they work, what the published evidence and major regulators say about benefits and harms, and practical expert tips for anyone considering them — especially women of childbearing age, people with medical conditions, and those wondering how to separate legitimate medical care from risky online shortcuts.
Serena Williams’ Weight Loss Before and After
Before:
After the births of her daughters—Alexis Olympia in 2017 and Adira River in 2023—Serena struggled with persistent postpartum weight gain, despite her elite athletic discipline. She described hitting a “wall” where, no matter how much she trained or how clean she ate, her body wouldn’t respond like before.
After:
In early 2024, about six months after ceasing breastfeeding, Serena began a medically supervised GLP-1 weight-loss regimen via Ro. By August 2025, she had shed around 31 pounds (about 14 kg) and shared feeling physically and mentally lighter, with improved energy, less joint pain, and greater ease in daily movement.
What are GLP-1 medications and how do they work?
GLP-1 receptor agonists (GLP-1 RAs) are injectable (and some oral) medications originally developed for type-2 diabetes. They mimic the gut hormone glucagon-like peptide-1 (GLP-1), which increases insulin secretion after meals, slows gastric emptying and reduces appetite. At higher doses, several GLP-1 drugs — including semaglutide (brand names such as Ozempic® for diabetes and Wegovy® for weight loss) and tirzepatide (Mounjaro®) — have been approved for chronic weight management because trials showed substantial, sustained weight loss when combined with lifestyle changes.
Why celebrities’ stories matter — and what they don’t show
When public figures like Serena Williams speak about GLP-1s, it raises awareness — but celebrity anecdotes don’t replace clinical guidance. Serena described using a GLP-1 as “part of what I’m doing” to feel healthier and manage joint pain; she emphasized it complemented training and diet rather than being a “shortcut.” That frankness helps destigmatize treatment for people who struggle with weight despite exercise and healthy eating. Still, individual responses vary widely, and what’s safe or appropriate for one person may not be for another.
What the evidence says about benefits
Large clinical trials of GLP-1 medications for obesity show meaningful, sustained weight loss (often 10–20% of body weight or more in trial settings), improvement in cardiovascular risk markers, and better glycemic control in people with diabetes. These drugs also often reduce appetite and food intake and improve markers such as blood pressure and blood sugar when used under medical supervision. But outcomes in the real world depend on dose, adherence, lifestyle changes and medical follow-up.
Common side effects — what patients usually experience
The most frequently reported adverse effects are gastrointestinal: nausea, vomiting, diarrhea, constipation and early satiety. For many patients these effects lessen over several weeks as the body adjusts. Rapid weight loss can also change facial fat distribution (sometimes described in media as “Ozempic face”), hair changes, and fatigue. Serious but rare risks reported in the literature include pancreatitis, gallbladder disease and hypoglycemia when combined with insulin or sulfonylureas. Longer-term safety data are still being gathered for the newest agents and combination drugs.
Special warnings: pregnancy, fertility and young people
Regulatory and clinical guidance emphasizes not using GLP-1s during pregnancy or if trying to conceive. Animal data and clinical caution show potential fetal harm or unknown risks; manufacturers and authoritative clinical summaries advise against use in pregnancy and recommend contraception while on therapy and for a time after stopping, depending on the drug. Women who are pregnant, breastfeeding or planning pregnancy should discuss alternatives with their clinician.
Safety concerns beyond side effects: unapproved products and dosing errors
The U.S. Food and Drug Administration (FDA) has warned about unapproved or counterfeit GLP-1 products sold online or via unscrupulous vendors—some labeled incorrectly for “research use” but sold with dosing instructions for people. These products may contain unknown ingredients, incorrect doses, or contamination. The FDA has also flagged dosing errors tied to compounded preparations and urged consumers to obtain GLP-1s only through licensed prescribers and reputable pharmacies. This is an important safety point: access via telehealth companies does not remove the need for proper medical evaluation and follow-up.
Mental health and quality-of-life considerations
Emerging research indicates mixed effects on mental health: while many people report improved mood and quality of life as weight and metabolic measures improve, some studies link GLP-1 use to slight increases in anxiety or mood symptoms in certain groups. Mental health screening and monitoring are advisable before and during treatment, especially in patients with prior anxiety or mood disorders.
Practical expert tips for patients considering GLP-1s
See a qualified prescriber first. A physician, nurse practitioner or endocrinologist can evaluate medical history, medications, pregnancy plans, and cardiometabolic risk before prescribing. Avoid buying injectables from unverified online sellers.
Discuss goals and duration. GLP-1s often work best as part of a long-term plan that includes diet, physical activity and behavior support. Ask your clinician how long you should remain on therapy and what follow-up will look like.
Start slow to reduce GI effects. Clinicians typically recommend dose-titration schedules to lessen nausea and vomiting — follow the prescribed ramp-up rather than self-adjusting.
Plan for contraception and pregnancy discussions. If you could become pregnant, discuss contraceptive plans and the timing of stopping medication well in advance of conception.
Monitor mental health. Report new or worsening anxiety, depression or eating-related distress to your provider promptly. Consider concurrent behavioral or psychological support.
Avoid mixed regimens without supervision. Combining GLP-1s with other metabolic drugs (or insulin) requires careful oversight to avoid hypoglycemia or other interactions.
Be wary of “cheap” or compounded versions. Compounded or black-market GLP-1s can carry dosing errors and contamination risks flagged by regulators. Buy only from licensed pharmacies tied to your prescriber.
Cost, access and telehealth — the real-world constraints
GLP-1s are effective but can be expensive. Some brand-name GLP-1s have limited coverage under insurance for weight management (coverage varies by plan and indication). Telehealth companies have expanded access, but the quality of care can vary: a remote visit that doesn’t include proper screening, periodic labs or follow-up can increase risk. Discuss insurance coverage, expected out-of-pocket cost and monitoring requirements before starting. (Serena Williams’ treatment was obtained via a telehealth service; while telehealth can be convenient, it’s important to ensure thorough medical evaluation.)
What clinicians are watching next
Researchers and regulators are closely watching long-term safety outcomes, rare adverse events and the broader public-health effects of mass GLP-1 use. Questions include the duration of therapy needed for durable benefit, metabolic effects after stopping therapy (weight regain is common without lifestyle changes), and population-level impacts on diabetes and cardiovascular disease risk. Clinicians also call for better access to multidisciplinary care — nutrition, physical therapy and behavioral health — to maximize benefits and reduce harms.
Bottom line
Serena Williams’ public account has helped normalize a medical approach that has clear benefits for many people but is not risk-free. GLP-1 medications can be powerful tools in the right clinical context, producing meaningful weight loss and metabolic improvements. However, they require medical oversight for safe prescribing, attention to pregnancy and mental-health issues, vigilance against unapproved products, and a plan for long-term lifestyle support. If you’re considering GLP-1 therapy, speak with a qualified clinician who will review your individual risks and goals, outline monitoring steps, and connect you to the support services that increase the chances of safe, lasting success.
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