Your Complete Guide to Managing Side Effects on GLP-1 Medication

⚠️ Seek Urgent or Emergency Care If...

• Severe, sudden chest pain, jaw pain, pain radiating down the left arm, numbness or tingling, difficulty breathing, or signs of a heart attack or stroke
• Vomiting blood, bright red blood after bowel movements, or black/tarry stools (signs of internal bleeding)
• Severe abdominal pain — right upper quadrant can indicate gallstones; left side radiating to back can indicate pancreatitis (rare)
• Sudden confusion, seizure, or loss of consciousness
• Severe allergic reaction: hives, swelling of face/throat, difficulty breathing
• Any thought of harming yourself — call 911 or the 988 Suicide & Crisis Lifeline

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01.  Nausea & Vomiting

Nausea is the most common side effect, affecting around 1 in 3  people starting GLP-1 medications. It is most noticeable in the first few weeks and during dose increases, and usually gets better as your body adjusts. Most commonly, it begins within 72 hours after an injection, peaking around 48 hours. It almost always improves with time and the right management strategies.

Diet & Eating Habits

• Eat 5–6 small meals throughout the day instead of 3 large ones
• Avoid high-fat, fried, greasy, or heavily spiced foods. 
• Stop eating as soon as you feel full — don't push through
• Stay upright for at least 2 hours after eating — avoid lying down
• Add small carbohydrate snacks (crackers, toast) to settle your stomach when needed

Natural Remedies

• Ginger tea, chews, or candies can ease mild nausea
• Peppermint tea or mints can calm an upset stomach
• Acupressure wristbands (available at pharmacies — often used for motion sickness)
• Stay well hydrated — take small sips on a schedule throughout the day and aim for 64–80 oz of water per day

Medication Options (Ask Your Provider)

• Vitamin B6 (10–25mg, up to 3x/day) — a gentle option; discuss dosing with your care team before starting
• If nausea interferes with daily life, your provider may slow dose titration or temporarily reduce your dose
• Tums or Pepto-Bismol — may help with stomach upset or heartburn that comes with nausea
• Over-the-counter motion sickness medicines (Nausene or Dramamine) may provide short-term relief but can cause drowsiness; ask your care team first
• Ondansetron (Zofran) — prescription anti-nausea medication if OTC options aren't enough

Seek Urgent or Emergency Care If…

• Vomiting that won't stop for more than 48 hours, especially with signs of dehydration (dark urine, dizziness, dry mouth)
• Severe stomach pain with vomiting
• Blood in your vomit or vomit that looks like coffee grounds
• "Dark, black, or tarry stools
• Vomiting combined with severe constipation or bloating (possible bowel blockage)
• Signs of dehydration: dizziness when standing, no urination for 8+ hours, very dark urine, or rapid heart rate
• High fever with vomiting or abdominal pain
• Confusion, extreme weakness, or inability to stay alert

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02. Acid Reflux / Heartburn / GERD

GLP-1 medications slow stomach emptying — food stays in the stomach longer, which can allow acid to back up into the esophagus. This affects around 15–30% of people. If you already have GERD, it may temporarily worsen.

Lifestyle Changes

• Elevate the head of your bed by 6–8 inches (use a wedge pillow or bed risers — extra pillows alone don't work as well)
• Don't lie down for at least 3 hours after eating
• Eat smaller meals and chew slowly
• Take a walk after eating to support digestion
• Sleep on your left side — this reduces acid exposure
• Wear loose clothing around your stomach area

Foods & Drinks to Avoid

• High-fat or fried foods, caffeine, alcohol, citrus fruits, tomato-based foods
• Spicy foods, carbonated beverages, and large meals eaten close to bedtime

Over-the-Counter Options (Ask Your Provider)

• Calcium carbonate (Tums) — as needed for quick relief
• Famotidine (Pepcid) — taken twice daily or before bed
• Omeprazole (Prilosec) — taken once daily before breakfast for ongoing symptoms. Talk to your care team before using for more than 2 weeks 
• Gaviscon (alginate) — creates a protective barrier on top of stomach contents to help prevent acid from backing up

⚠️ Seek Urgent or Emergency Care If…

• Difficulty swallowing or pain when swallowing
• Chest pain not clearly related to meals, or that radiates or comes with shortness of breath
• Vomiting blood or black/tarry stools
• Bad stomach pain that spreads to your back
• Choking, a cough that won't go away, or a hoarse voice that doesn't improve
• Unexplained weight loss along with persistent heartburn

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03. Fatigue

Feeling more tired than usual affects about 11–16% of people on GLP-1 medications. Common causes include eating fewer calories, mild dehydration, poor sleep, or your body simply adjusting to the medication.

Nutrition

• Make sure you're eating balanced meals (protein, complex carbs, fruits, veggies, healthy fats) at regular intervals throughout the day (e.g. every 3–4 hours)
• Prioritize protein with every meal and snack
• Include complex carbohydrates (oats, whole grains, sweet potatoes) for lasting energy
• Eat on a schedule, not just when you feel hungry — your hunger signals are quieter on this medication, so waiting until you feel hungry may mean waiting too long
• If your meals feel very small or you're eating less often than usual, talk to your care team about whether your intake is enough

Lifestyle

• Aim for 7–9 hours of sleep each night — eat your last meal at least 2–3 hours before bed, and keep a consistent bedtime and wake time
• Gentle movement like short 10–15 minute walks can actually boost energy. Even on low-energy days, light activity helps more than complete rest
• Drink 64–80 oz of fluid daily — dehydration is a sneaky cause of fatigue

Supplements to Discuss with Your Provider

• Vitamin B12 (1,000 mcg/day) — especially if you take Metformin, which can lower B12 levels over time (over 6 months)
• Vitamin D (2,000–4,000 IU/day) — discuss with provider or dietitian if more is recommended
• Iron — if your ferritin level is below 30 ng/mL

⚠️ Seek Urgent or Emergency Care If…

• Chest pain or shortness of breath — possible cardiac event or pulmonary embolism
• Confusion, trembling, or sweating — possible low blood sugar (hypoglycemia)
• Cold intolerance or unexplained weight gain — possible thyroid issue (call your doctor)

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04. Constipation

Constipation (fewer than 3 bowel movements per week) usually affects 17-24% of people on GLP-1 medications because these medications slow the movement of food through your digestive tract. Eating less and drinking less fluid — both common on GLP-1 therapy — can also contribute. 

Dietary Fiber

• Gradually increase dietary fiber to 25g/day (women) or 35g/day (men) — go slowly to avoid gas
• Try psyllium fiber (Metamucil) — 1 tablespoon in water, twice daily, with increased water intake
• Good fiber sources: chia seeds, fruits (especially kiwi), vegetables, sweet potatoes, legumes, whole grains, flaxseeds

Hydration

• When increasing fiber, drink more water — 64–100 oz per day is a good target — your care team can help you find the right amount
• Warm liquids in the morning (warm water with lemon) can help stimulate bowel movements. 
• GLP-1 medications can reduce your sense of thirst, so drink on a schedule rather than waiting until you feel thirsty.

Over-the-Counter Options (Ask Your Provider)

• Polyethylene glycol (MiraLAX) — gentle and effective, 17g once daily
• Magnesium citrate — 200–800mg before bed (start low, increase slowly). Use with caution if you have kidney problems.
• Docusate (Colace) — stool softener for hard stools, 100–200mg twice daily

⚠️  Seek Urgent or Emergency Care If…

• No bowel movement for 5+ days with severe pain, bloating, a hard abdomen, or inability to pass gas
• Bright red blood in your stool — seek urgent care or the ER
• Sudden severe stomach pain that spreads to your back, especially after eating — this could be a sign of pancreatitis, a rare but serious side effect

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05. Diarrhea

Loose stools or diarrhea can occur, especially in the first few weeks or during dose increases. It is less common than nausea or constipation and usually improves as your body adjusts. Certain foods are known triggers.

Diet Tips

• During flares, focus on bland, low-fat foods: bananas, white rice, applesauce, toast, cooked carrots, plain chicken
• Avoid high-fat and/or greasy foods, and sugar alcohols (sorbitol, xylitol found in some "sugar-free" products)
• A soluble fiber supplement may help bulk stool if prolonged (e.g. Metamucil). If you recently increased fiber intake, slow down — too much too fast can cause or worsen diarrhea. Focus on soluble fiber (oats, bananas, cooked carrots) and temporarily reduce insoluble fiber (raw vegetables, bran, nuts, seeds).
• Stay well hydrated — diarrhea causes fluid and electrolyte loss. Sip water, broth, or an oral rehydration solution (Pedialyte, Liquid IV) throughout the day. Don't rely on plain water alone if diarrhea is frequent

Medication Adjustments & OTC Options

• If on Metformin IR, always take it with a full meal — or ask your provider about switching to Extended Release (ER), which is much gentler on the stomach
• Loperamide (Imodium) — slows gut movement; short-term use. Ask your care team first.
• Bismuth subsalicylate (Pepto-Bismol) — may help reduce loose stools. Do not use if you have fever or blood in your stool

⚠️ Seek Urgent or Emergency Care If…

• More than 7 loose stools in a single day, or diarrhea lasting more than 2–3 days without improvement
• Blood or mucus in your stool
• Signs of dehydration: dizziness, dark urine, dry mouth, no urination for 8+ hours
• Diarrhea with fever

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06. Mood Changes & Loss of Pleasure (Anhedonia)

Some people on GLP-1 medications report feeling emotionally 'flat' — with less joy, reduced motivation, or a general blunting of emotions. Doctors call this anhedonia. Large studies have not found that GLP-1 medications cause mood problems more often than inactive treatment, but if you notice a change in how you feel emotionally, it is worth paying attention to. 

What to Do

• If you have a history of depression or anxiety, let your care team know before starting or increasing your dose — monitoring is especially important for people with a history of mood conditions
• Track when the feeling started — was it shortly after starting or increasing your dose?
• Keep in mind that mood changes during weight loss can have many causes — changes in eating patterns, sleep disruption, life stress, or pre-existing mood conditions can all play a role
• Complete a PHQ-9 depression screening (available online or from your provider)
• Regular exercise (20–30 minutes daily) and social engagement can help
• Talk to your provider — a temporary dose reduction may help determine if medication is the cause

⚠️  Seek Urgent or Emergency Care If…

• Thoughts of self-harm or suicide — call 911 or the 988 Suicide & Crisis Lifeline
• Hearing or seeing things that aren't there, or severe confusion — seek emergency care immediately
• Any mood symptoms that feel severe or frightening — contact your provider the same day

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07. Not Eating Enough (Undereating)

GLP-1 medications powerfully suppress appetite — which is great for weight loss, but some people suppress too much, eating fewer than 1,000 calories per day. This can lead to muscle loss, fatigue, hair loss, and nutritional deficiencies.

Your Minimums

• Women: at least 1,200 calories per day
• Men: at least 1,500 calories per day
• Protein: aim for 1.2–1.6 grams per kilogram of body weight per day to help preserve muscle (or roughly 80–120 grams per day as a practical target) 

Tips for Getting Enough Nutrition

• Focus on calorie-dense foods: nuts, nut butter, avocado, olive oil, eggs
• Eat on a schedule — don't wait until you feel hungry. GLP-1 medications quiet your hunger signals, so waiting until you feel hungry may mean waiting too long.
• Be sure to eat protein first at each meal — when appetite is low, eating protein before other foods helps make sure you get enough
• Use liquid nutrition: protein shakes, smoothies, Greek yogurt
• Set scheduled eating times — don't wait until you're hungry, because your hunger cues may be blunted
• If you struggle to eat enough, schedule an appointment with your registered dietitian

⚠️ Contact Your Care Team If:

• You are consistently eating fewer than 800 calories per day or unable to eat enough to meet basic needs
• You are losing weight faster than expected (more than 1–2 lbs per week consistently)
• You are experiencing hair loss and fatigue together
• You have a history of or are developing signs of disordered eating — fear of eating, guilt around food, or restrictive thoughts about food

Seek Urgent or Emergency Care If:

• Fainting, severe dizziness, or confusion — may indicate dangerously low intake or dehydration
• Chest pain, rapid heartbeat, or shortness of breath

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08. Hair Loss

Hair shedding is common during rapid weight loss.. This is called telogen effluvium — a temporary condition where hair follicles shift into a resting phase due to the stress of rapid weight loss or lower calorie intake. Hair shedding usually starts 2–4 months after the trigger and typically stops within 3–6 months once the trigger is removed. Hair regrows on its own in most cases.

Nutritional Support

• Protein: 1.2–1.6g per kg body weight per day — this is the most important factor
• Biotin: 5,000–10,000 mcg daily (available over the counter). Important: biotin supplements can interfere with certain lab tests, including thyroid and heart tests — let your care team know if you are taking biotin before any blood work.
• Zinc: 15–30mg daily
• Ask your provider to check Ferritin and Vitamin D levels. Low ferritin is one of the most common and fixable causes of hair shedding — your provider will determine the right target for you. Vitamin D target: above 30 ng/mL.

Scalp & Hair Care

• Handle hair gently — avoid tight styles, aggressive brushing, or excessive heat
• Use a wide-tooth comb and gentle, sulfate-free shampoo
• Ask a dermatologist about low-dose Minoxidil if shedding is significant

⚠️  Seek Urgent or Emergency Care If…

• Sudden clumps of hair falling out all at once — possible alopecia areata
• Patchy, circular bald spots — possible autoimmune hair loss
• Scalp redness, inflammation, or scarring — may a skin biopsy to diagnose

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09. Indigestion & Bloating

Discomfort, bloating, and feeling full very quickly (early satiety) affects roughly 7–10% of people on GLP-1 medications.  GLP-1 medications slow how quickly your stomach empties, which can cause these symptoms. They usually improve as your body adjusts to the medication.

Tips

• Eat small, frequent meals throughout the day
• Chew food slowly and thoroughly — this reduces the amount of air you swallow and helps digestion
• Avoid gas-producing foods: beans, broccoli, cabbage, carbonated drinks
• Simethicone (Gas-X) can relieve gas pain — 80–125mg as needed
• A short walk after meals can help move food through your stomach
• If bloating comes with heartburn or acid reflux, an H2 blocker (Famotidine/Pepcid) or PPI (Omeprazole/Prilosec) may help — talk to your care team before using a PPI for more than 2 weeks

⚠️  Seek Urgent or Emergency Care If…

• Severe abdominal pain, especially with vomiting or inability to pass gas — possible bowel obstruction
• Severe nausea and vomiting that prevents you from eating or drinking — may need evaluation for gastroparesis

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10. Headache

Headaches affect 10–17% of people and are most commonly caused by mild dehydration, low blood sugar, or caffeine withdrawal during early treatment.

Prevention & Relief

• Drink at least 64–80 oz of water per day — dehydration is the #1 cause
• Eat regular meals to keep blood sugar stable
• Aim for 7–9 hours of sleep each night
• For pain relief: Acetaminophen (Tylenol) 500–1,000mg every 6 hours, or Ibuprofen 400–600mg every 6–8 hours with food (if no contraindications)
• If you've cut back on caffeine, taper slowly rather than stopping abruptly

⚠️  Seek Urgent or Emergency Care If…

• You have a sudden, severe "thunderclap" headache — the worst headache of your life — possible brain bleed
• Headache is accompanied by fever, stiff neck, or light sensitivity — possible meningitis and needs evaluation
• Headache with vision changes, especially new or worsening blurry vision or loss of vision in one eye

Most headaches on GLP-1 medications are mild, happen early on, and get better as your body adjusts. Staying hydrated and eating regularly are the two most effective ways to prevent them.

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11. Dizziness & Lightheadedness

Dizziness affects about 4–8% of people on GLP-1 medications and is usually related to mild dehydration or a drop in blood pressure when standing up quickly (orthostatic hypotension. 

What Helps

• Drink at least 64–80 oz of fluid per day — and more if you are experiencing nausea, vomiting, or diarrhea
• Rise slowly from sitting or lying positions — pause at the edge of the seat before standing
• Compression stockings can help if you tend toward low blood pressure
• If you take blood pressure medications, tell your provider — the dose may need adjustment as you lose weight
• Check blood sugar if you're on medications that can cause low glucose

⚠️ Seek Urgent or Emergency Care If…

Contact Your Care Team If:

• Dizziness is happening frequently or not improving with increased fluids and regular meals
• You feel lightheaded every time you stand up
• You take blood pressure medication and are noticing lower readings or more dizziness as you lose weight

Seek Urgent or Emergency Care If:

• Dizziness with chest pain, shortness of breath, or a rapid or irregular heartbeat
• Sudden severe dizziness with difficulty walking, speaking, or seeing — possible stroke
• Fainting or near-fainting that does not resolve quickly
• Dizziness with sudden severe headache, especially "the worst headache of your life

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12. Injection Site Reactions

Mild redness, itching, bruising, or firmness at injection sites is normal and affects 2–8% of people. These reactions are usually minor and temporary.

Injection Technique Tips

• Rotate injection sites each week — abdomen, upper thigh, and upper arm are all options
• Let the medication warm to room temperature (15–30 minutes out of the refrigerator) before injecting
• If injections are uncomfortable, applying an ice pack or cold compress to the area for a few minutes beforehand can help numb the skin
• Follow the injection instructions that came with your specific pen. Most pens are designed to be placed flat against the skin and do the rest automatically.

For Mild Reactions

• Apply hydrocortisone 1% cream to the area for redness or itching
• Oral antihistamines (Benadryl, Claritin) can help with itching

⚠️  Seek Urgent or Emergency Care If…

• The injection site becomes increasingly red, warm, swollen, or painful with pus or streaking — signs of infection
• You develop hives, swelling of your face, lips, or throat, or difficulty breathing after injecting — this is a severe allergic reaction. Call 911 immediately
• Do not use this medication again until you have spoken with your care team

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13. Low Blood Sugar, Sleep & Anxiety

Low Blood Sugar (Hypoglycemia)

GLP-1 medications alone rarely cause low blood sugar. Symptoms include shakiness, sweating, rapid heartbeat, confusion, and hunger.

• Know the "Rule of 15": Eat 15 grams of fast-acting carbs, wait 15 minutes, and re-evaluate
• Examples: 4 glucose tablets, half a cup of orange juice, 1 tablespoon of honey
• Talk to your provider about adjusting your insulin or sulfonylurea dose when starting a GLP-1

Insomnia & Anxiety

Insomnia (14–18%) and anxiety (5–8%) are most common with Contrave (bupropion/naltrexone). These usually improve with timing and sleep hygiene adjustments.

• Take Contrave in the morning and early afternoon — never close to bedtime
• If nausea from injectable GLP-1 keeps you awake, try injecting after dinner
• Limit caffeine after noon; avoid screens for 1–2 hours before bed
• Maintain a consistent sleep schedule, even on weekends

⚠️ Seek Urgent or Emergency Care If…

• You have severe confusion, seizure, or loss of consciousness from low blood sugar — call 911
• You experience severe anxiety, panic attacks, or any thoughts of self-harm — call 911 or 988
• New manic episodes or extreme mood elevation with insomnia — stop Contrave and seek emergency psychiatric care

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14. Quick Reference: When to Seek Care

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15. Tips for Success

✓  Do

• Keep a symptom journal to track when side effects occur and what triggers them
• Stay consistent with hydration — most side effects improve with adequate fluids
• Communicate openly with your care team — never hesitate to reach out
• Give yourself grace during the adjustment period — the first 4–12 weeks are often the hardest
• Celebrate non-scale victories: better energy, improved labs, clothes fitting better

✗  Avoid

• Don't skip meals to manage nausea — an empty stomach often makes nausea worse, creating a cycle that is hard to break
• Stop your medication abruptly without talking to your provider first
• Ignore symptoms that feel severe or unusual
• Don't rely only on thirst to remind you to drink — this medication can reduce your sense of thirst, so drink on a schedule throughout the day
• Don't eat large, high-fat, or spicy meals — especially in the first few days after your injection when side effects are most likely
• Compare your experience to others — everyone responds differently

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💡You Are Not Alone
Side effects can feel discouraging, but most are temporary and a sign your body is adjusting to the medication. With the right strategies and support from your care team, most people find they can manage symptoms effectively. Your health journey is worth it.
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Questions? Reach out to your care team anytime — that is what we are here for.

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_{This handout is for educational purposes only and does not replace personalized medical advice from your healthcare provider. Always consult your Onsera care team before making changes to your medications or treatment plan.}