The most common Wellbutrin (bupropion) side effects in the first week are dry mouth, headache, trouble sleeping, nausea, and feeling shaky or on edge. Wellbutrin is more likely to leave you wired than sleepy. A review of bupropion data calls it "well tolerated," but a seizure, a rash with swelling, or new thoughts of self-harm need help right away.
Some of these complaints happen on a sugar pill too. In the FDA label's placebo-controlled depression trials, headache hit 26% of people on bupropion SR and 23% of people on placebo. Dry mouth was different: 17% on bupropion SR versus 7% on placebo. Knowing which is which makes week one a lot less scary.
This article provides general information about medication management and is not a substitute for professional medical advice. Always consult your doctor or pharmacist before making changes to your medication schedule.
How Common Are Wellbutrin Side Effects in the First Week?
Wellbutrin isn't an SSRI. The label states that bupropion inhibits the reuptake of dopamine and norepinephrine, two "get up and go" brain chemicals. That may be why its early side effects often feel more like too much coffee than a sleepy fog.
The table comes from the Wellbutrin XL prescribing information. The depression numbers are from trials of the sustained-release (SR) version, and the XL numbers are from seasonal depression trials. The label says the versions have similar bioavailability. These are rates over the whole trial, not just week one.
| Side effect | Depression trials (SR): placebo vs bupropion | Seasonal trials (XL): placebo vs bupropion |
|---|---|---|
| Headache | 23% vs 26% | 26% vs 34% |
| Dry mouth | 7% vs 17% | 15% vs 26% |
| Trouble sleeping | 6% vs 11% | 13% vs 20% |
| Nausea | 8% vs 13% | 8% vs 13% |
| Constipation | 7% vs 10% | 2% vs 9% |
| Dizziness | 5% vs 7% | 5% vs 6% |
| Tremor (shakiness) | 1% vs 6% | under 1% vs 3% |
| Sweating | 2% vs 6% | not listed |
| Ringing in the ears | 2% vs 6% | under 1% vs 3% |
| Anxiety | 3% vs 5% | 5% vs 7% |
| Agitation | 2% vs 3% | under 1% vs 2% |
Source: Wellbutrin XL prescribing information, Tables 3 and 4. SR column shows the usual target dose group.
Dry mouth stands out. It has the biggest gap over placebo in both sets of trials, so if your mouth feels like cotton, that one is probably the pill. Headache is the opposite case: placebo takers got headaches almost as often.
Dose matters too. In the same depression trials, the higher-dose group had more dry mouth (24%), trouble sleeping (16%), and agitation (9%), and the generic bupropion SR label says dry mouth and insomnia "may be related to the dose."
Only a small group quit over side effects: 9% on bupropion SR versus 4% on placebo in the depression trials.
What to Expect in Your First Week on Wellbutrin
No label gives a day-by-day timeline, so treat this as a rough map, not a promise.
Days 1 to 3. Any of the side effects in the table above can start once you begin taking it. Blood levels are still climbing: the label says bupropion reaches steady state within about 8 days.
Days 4 to 7. The label tells prescribers to start low and increase the dose gradually, partly to lower seizure risk. If your prescriber planned a step up in week one, you may notice side effects more right after it, since several of them track with dose.
The mood part. Don't expect your depression to lift yet. MedlinePlus says it may take 4 weeks or longer to feel the full benefit. Side effects first, benefits later is the normal order. Our week-by-week guide to starting antidepressants picks up from week two.
Does Wellbutrin Make You Tired or Wired at First?
More often wired than tired, though either can happen. MedlinePlus does list drowsiness as a possible side effect. The tilt toward wired is the biggest way your first week differs from someone starting sertraline or another SSRI.
A review of 15 years of bupropion data found that sleepiness (somnolence) rates were higher in SSRI-treated patients than with bupropion. The same review found bupropion was "consistently" linked to less sexual dysfunction than SSRIs. A survey of 6,297 patients in U.S. primary care put sexual dysfunction at 22% to 25% on bupropion versus 36% to 43% on SSRIs and similar drugs. Lower, not zero.
For the SSRI version of this week, see our first week on sertraline guide.
Is It Normal for Wellbutrin to Make You Anxious or Shaky?
Some jitters are common. In the label trials, tremor, sweating, anxiety, and agitation all ran a few points above placebo, and "feeling jittery" is listed as a side effect on its own. Tell your prescriber about it. The Medication Guide says to call right away if anxiety or restlessness is new, getting worse, or worries you.
But the label draws a clear line. It lists anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (severe inner restlessness), hypomania, and mania as symptoms to report right away, especially if they're severe, sudden, or new for you. Restlessness so strong you can't sit still, or feeling angry and unlike yourself, is a call-now symptom, not a wait-and-see.
Can't Sleep During Your First Week on Wellbutrin?
Trouble sleeping was the top reason people in the XL seasonal trials stopped the drug, though still only 2% versus under 1% on placebo. In week one, the first thing to check is simple: when are you taking it?
The label says Wellbutrin XL is taken in the morning. A bupropion review explains why: with a morning XL dose, evening blood levels are lower than with the twice-daily SR version, which "may result in a lower rate of insomnia." The generic SR label adds that insomnia "may be minimized by avoiding bedtime doses."
Don't move your dose on your own. Ask your prescriber or pharmacist if the timing can change. For the full timing rules for each version, see the best time to take bupropion. If you already took it at night by mistake, read accidentally took bupropion at night.
How Big Is the Wellbutrin Seizure Risk?
Seizure risk is the warning bupropion's label puts front and center. The label says Wellbutrin can cause seizures and the risk is dose-related.
It's uncommon. The label reports about 0.1% (1 in 1,000) with the SR version at usual doses, and about 0.4% with the older immediate-release version in the range of 300 mg to 450 mg per day that was studied. The 102-center study behind that figure followed 3,341 patients and found 0.40% over the whole study (0.24% in its 8-week treatment phase). The risk rises steeply at very high doses.
That's why three simple rules from the label matter so much in week one:
- Never take an extra tablet to catch up. If you miss a dose, the label says not to take an extra tablet and to take the next one at the regular time "because of the dose-related risk of seizure." If you're unsure what to do, ask your pharmacist. More in our missed dose of bupropion guide.
- Space doses the way your version needs. XL doses go at least 24 hours apart. SR doses go at least 8 hours apart.
- Swallow tablets whole. Crushing or chewing releases the drug too fast, which the Medication Guide says makes side effects, including seizures, more likely.
Tell your prescriber about any history of seizures, eating disorders, or head injury, or if you're suddenly stopping alcohol, benzodiazepines, or seizure medicines. Also tell them if you've taken an MAOI antidepressant in the last 14 days, since the label doesn't allow the two together. If you took two by mistake, read accidentally took a double dose of bupropion.
Wellbutrin Side Effects in Women During the First Week
The label lists a few side effects that apply only to women. In the older immediate-release trials, menstrual complaints showed up in 5% versus 1% on placebo. In the XL seasonal trials, painful periods were reported in 2% versus under 1%.
Sexual side effects are a common worry. In that primary care survey, most of the 6,297 patients were women (4,534), and bupropion had among the lowest sexual dysfunction rates of the drugs studied.
Weight is the other one. Bupropion is more often linked to weight loss than gain. In the depression trials, 14% on bupropion SR lost more than 5 pounds versus 6% on placebo. That's over weeks, not days.
If you're pregnant or planning to be, talk with your prescriber before making any change. Untreated depression carries its own risks, the label notes.
What Does the Wellbutrin Black Box Warning Mean?
Like other antidepressants, Wellbutrin carries a boxed warning. The label says antidepressants increased the risk of suicidal thoughts and behavior in children, teens, and young adults in short-term trials. The increase showed up in people under 25. It did not show up in people 65 and older.
Still, the label says people of all ages should be watched closely when starting, especially in the first few months and after any dose change. The label also asks families and caregivers to watch for these changes every day.
If you have thoughts of harming yourself, call or text 988 (the Suicide and Crisis Lifeline) or call 911.
Is It the Wellbutrin, or Something Else?
Before you blame the pill, check these other possibilities:
- Headache, nausea, and dizziness were common on placebo too. The table above shows how much of each is likely the drug.
- Diarrhea wasn't more common on bupropion. In the depression trials, diarrhea hit 6% on placebo and 5% on bupropion SR. A stomach bug or diet change may be the real cause.
- If you're taking bupropion to quit smoking, nicotine withdrawal can cause irritability, anxiety, trouble sleeping, restlessness, and more, with or without the drug. But if you notice agitation, hostility, low mood or behavior changes, stop taking it and call your prescriber right away.
- Depression itself can look like a side effect. Trouble sleeping, low energy, and an anxious mood are common symptoms of depression. The label warns to watch for depression getting worse, which is a reason to call, not to wait it out.
- Bupropion can raise blood pressure, and the risk is higher with a nicotine patch. The label says blood pressure should be checked before you start and from time to time after.
Alcohol is its own topic. The label says to minimize or avoid it. See Wellbutrin and alcohol for details.
When to Call a Doctor in Your First Week on Wellbutrin
MedlinePlus lists these as reasons to get emergency help. Call 911 for:
- A seizure. The label says not to take it again if you have a seizure.
- Trouble breathing, or swelling of the face, lips, tongue, or throat. Stop taking bupropion and get help.
- Confusion, or seeing or hearing things that aren't there. The label says to stop the drug if these happen.
- Thoughts of suicide or self-harm (or call or text 988)
For a rash, hives, blisters, or itching, the label says to stop taking it and contact your provider if an allergic reaction starts, and MedlinePlus lists fever with rash in the same group.
Call your prescriber right away for:
- Severe restlessness, agitation, anger, or panic
- Fast, pounding, or irregular heartbeat
- Signs of mania: racing thoughts, much less need for sleep, reckless behavior
- Eye pain, changes in vision, or swelling or redness around the eye, since the label warns about a rare type of glaucoma
For milder side effects that stick around, tell your prescriber at your next visit. Don't stop Wellbutrin on your own.
How Pillo Helps in Your First Week
Pillo's persistent alarm keeps going until you respond, so your morning dose happens in the morning, not at 9 p.m. when you finally remember. If you do miss one, the reminder is a nudge, not a reason to double up. Follow the skip rule above.
You can also log mood, sleep, and blood pressure in Pillo's health trackers, and add a dose note like "dry mouth, mild headache." By your first follow-up, you'll have a real record instead of a fuzzy memory.
Frequently Asked Questions
How long do Wellbutrin side effects last?
The FDA label doesn't give a timeline for how long early side effects last, and it doesn't promise they fade. That's why MedlinePlus tells you to report side effects that are severe or don't go away. Dose and timing matter too: the label ties dry mouth and trouble sleeping to dose, so bring them up at your follow-up.
Is it normal to feel anxious the first week on Wellbutrin?
A mild jittery feeling is common. In the label trials, anxiety affected 5% on bupropion SR versus 3% on placebo. The Medication Guide says to call your prescriber right away if anxiety, panic attacks, or agitation are new, getting worse, or worry you.
Can Wellbutrin make you angry or irritable at first?
It can. Irritability and hostility are on the label's list of symptoms to report right away, especially if they're new, getting worse, or worry you. In the older immediate-release trials, hostility showed up in 6% versus 4% on placebo. Don't wait for your next appointment if you feel unlike yourself.
Does Wellbutrin cause diarrhea in the first week?
Not more than placebo, based on the label. In the depression trials, diarrhea affected 5% on bupropion SR and 6% on placebo. Constipation was a bit more common on bupropion (10% versus 7%).
Why do my Wellbutrin pills smell?
The Wellbutrin XL Medication Guide says the tablets may have an odor and that this is normal. If a pill looks damaged or different from your last refill, ask your pharmacist.
Medical Disclaimer
This article provides general information about medication management and is not a substitute for professional medical advice. Consult your doctor or pharmacist for advice specific to your medications.
