Medical Review by Jennie Stanford, MD, FAAFP, DipABOM
Summary
- Prozac® (fluoxetine) is an SSRI used to treat a variety of conditions including depression. It boosts serotonin, which helps regulate your mood, sleep, stress, and emotions.
- Common side effects during the first week may include headaches, nausea, diarrhea, and fatigue. These usually improve as your body adjusts to the medication.
- To manage side effects, try simple remedies like keeping hydrated, reducing caffeine, and adjusting the time of day you take Prozac®.
- Serious side effects are rare but may include suicidal thoughts, seizures, and serotonin syndrome. Contact a healthcare provider immediately if you experience any severe symptoms.
Here’s what you need to know as you start taking Prozac®
Prozac®, the brand name for the medication fluoxetine, is a commonly prescribed antidepressant that belongs to a group of medications known as selective serotonin reuptake inhibitors (SSRIs). When you take an SSRI such as Prozac®, it prevents serotonin from being reabsorbed too quickly, allowing more of it to stay in the brain. Serotonin helps regulate your mood, sleep, stress, appetite, sex drive, and emotions.
Prozac® is FDA approved to treat:
- Depression
- Obsessive compulsive disorder
- Bulimia nervosa
- Panic disorder
Most people respond well to Prozac®, but you might notice some side effects during the first week. Knowing what to expect and being prepared can help you manage this adjustment period more smoothly.
In this article, we’ll guide you through what to expect during your first week on Prozac®, provide tips for managing side effects, and explain when to seek help from a healthcare professional.
What to expect in the first week
When you start taking Prozac®, your body needs time to adjust. You might have some mild side effects, but these usually don’t last long and should go away as your body adapts. Keep in mind it could take approximately 5 weeks before you start feeling the full benefits of Prozac®.
Learn more: Fluoxetine (Prozac): Uses, Benefits, Side Effects, & More
Most common side effects
- Headaches
- Nausea
- Diarrhea
- Indigestion
- Weakness and lacking energy
- Dry mouth
- Excessive yawning
- Unusual dreams
- Insomnia
- Flu-like symptoms
- Tremors
- Feeling anxious or nervous
- Loss of appetite and weight loss
These aren’t the only possible side effects, as everyone reacts differently to medication. We’ve covered the most common ones here, but we’ll also go over some rare yet serious side effects later, so you know what to watch out for.
Tips for the first week
To help prevent or manage side effects, here are some tips to make things easier. These general guidelines help manage side effects of numerous SSRIs, including Prozac®:
- To ease a headache or migraine: rest in a quiet, dark room, stay hydrated, use over-the-counter pain relievers, and try gentle massage techniques.
- To ease nausea: take Prozac® with a small amount of food, like crackers or toast. Foods and drinks that contain ginger may also help.
- To stop diarrhea: take an antidiarrheal medication or psyllium husk may also be effective.
- To moisten a dry mouth or a sore throat: drink plenty of water, chew sugarless gum, or suck on sugarless candy. Avoid caffeine, tobacco, and alcohol, as they can make dry mouth worse.
- To help with fatigue: If you’re feeling tired during the day, try taking your medication later in the evening.
- To reduce tremors, anxiety, or agitation: reduce your caffeine intake.
Ensure that you look after yourself, drink lots of water, get a good night’s sleep, and exercise regularly. These habits will help you to feel better during your first week of taking Prozac®.
When to seek help
Prozac® is considered safer and has fewer side effects compared to many other antidepressants, however, rare serious side effects can still occur. Contact your provider immediately if you experience any of these serious symptoms:
- Suicidal thoughts or behaviors—people aged 24 and younger have a higher risk, especially in the first few months of treatment or after a dose change
- An extreme increase in activity or talking (mania), which can be a risk for those with bipolar disorder
- Seizures
- Allergic reaction—rash, trouble breathing, swelling of the face, tongue, eyes or mouth
- Changes in appetite and weight
- Changes in vision or eye pain
- Unusual bleeding—this may occur when SSRIs are taken with aspirin, nonsteroidal anti-inflammatory drugs, antiplatelet drugs, warfarin, or other anticoagulants
- Sexual dysfunction
The risk of serotonin syndrome when taking Prozac®
SSRIs, including Prozac®, may cause serotonin syndrome, especially when used with other medications that affect serotonin levels. This condition is serious and even life-threatening.
Watch out for these symptoms of serotonin syndrome:
- Changes in mental state, such as agitation, hallucinations, confusion, or delirium
- Fast heartbeat or changes in blood pressure
- Sweating and flushing
- Tremors
- Stiff muscles or muscle twitches
- Seizures
- Dizziness
- Nausea, vomiting, and/or diarrhea
If you are concerned that you might be experiencing early signs of serotonin syndrome, get in-person medical attention as soon as possible.
Consulting your healthcare provider
When starting a new medication, it’s important to pay attention to how you feel. Try noting down any changes you notice so you can discuss them with your healthcare provider. Regular check-ins will help them monitor your progress and make adjustments if needed.
If your healthcare provider decides that your dosage needs to be adjusted, don’t worry—this is a normal part of finding what works best for you. Just keep taking Prozac® exactly as prescribed, and be sure not to adjust your dosage by yourself.
Managing your Prozac® journey with Lemonaid Health
Starting Prozac® can feel easier when you’re well-prepared and take it consistently. Staying in touch with your healthcare provider helps make the transition smoother. You might notice side effects in the first week, but they usually get better over time—and if you have any serious concerns, help is available.
Our team at Lemonaid Health can help. Get started here with a qualified US-based health professional who can help you understand your symptoms and find appropriate solutions, including FDA-approved medication in clinically indicated cases.
Prozac® is a registered trademark of Eli Lilly and Company.
