Anti-Anxiety Medications Compared: Side Effects Matter More Than Strength

You finally decided to try medication for anxiety, and the pharmacy printout lists two dozen side effects in tiny type. A friend swears by a pill that works in 20 minutes, while your prescriber suggests one that takes weeks. It’s fair to wonder which of those side effects you should actually plan for.

Your anxiety runs on more than one system. Serotonin pathways shape how loud worry gets over weeks, GABA acts as your brain’s fast brake, and adrenaline drives the pounding heart. Each medication pulls on one of those levers, and its side effects follow the same lever with real precision: a drug that raises serotonin acts wherever serotonin acts, and a drug that presses the GABA brake slows more than worry.

The standard approach to choosing among them is well studied. SSRIs and SNRIs are first-line medications for generalized anxiety, panic disorder, and social anxiety, according to a 2020 pharmacotherapy review, and a 2019 Lancet meta-analysis of 89 trials found that escitalopram, duloxetine, venlafaxine, and pregabalin outperformed placebo with relatively good acceptability. The results are real, and the evidence base is deep.

But a printed list of side effects can’t tell you which ones will show up for you or when, and at Siggy we’d rather plan for side effects before your first dose than react after you’ve already quit.

This guide compares the main options by what shapes daily life: how fast each helps, which side effects are common, what the FDA warns about, and what happens when you stop. The right medication is the one your body can tolerate long enough for the benefit to arrive, and that choice should rest on evidence.

What This Page Covers

• How Do Anti-Anxiety Medications Compare?
• What Side Effects Do SSRIs and SNRIs Cause?
• Why Can Anxiety Feel Worse Before It Gets Better?
• What Are the Side Effects of Buspirone?
• What Are the Side Effects of Hydroxyzine?
• Why Are Benzodiazepines Prescribed Short Term?
• What Happens When You Stop an Anxiety Medication?
• When Is a Side Effect an Emergency?
• How Siggy Approaches Anxiety Medication Side Effects
• Plan for Side Effects Before Your First Dose

How Do Anti-Anxiety Medications Compare?

For the main medication classes, the biggest differences are speed, side effects, and dependence risk rather than raw strength. In a 2024 meta-analysis of 122 trials, benzodiazepines improved anxiety faster in the first week, but by week 8 SSRIs, SNRIs, and benzodiazepines produced similar results overall.

The table pairs those onset patterns, plus buspirone’s timeline from the 2020 review, with the side effects each label lists most often.

Medication Class	How Fast It Helps	Common Side Effects	Stopping and Dependence
SSRIs and SNRIs	Gradually, over weeks	Nausea, headache, sleep changes, sexual effects	Taper to limit discontinuation symptoms
Buspirone	About 10 days to 4 weeks	Dizziness, nausea, headache	No evidence of tolerance or dependence
Hydroxyzine	Usually 15 to 30 minutes	Drowsiness, dry mouth	Not a controlled substance
Benzodiazepines	Within the first week	Drowsiness, dizziness, weakness	Boxed warning for dependence and withdrawal
Propranolol (off-label)	Peaks at 1 to 4 hours	Fatigue, lightheadedness, cold hands	Taper if taken daily

The label data come from escitalopram’s FDA label, the buspirone label, the hydroxyzine label, the FDA benzodiazepine warning, and the propranolol label.

Propranolol earns its row because many people use it for shaky hands before big moments, though a 2025 meta-analysis found no robust evidence that beta blockers treat anxiety disorders. Our propranolol timing guide explains where it fits.

What Side Effects Do SSRIs and SNRIs Cause?

SSRIs such as escitalopram and sertraline, and SNRIs such as venlafaxine and duloxetine, are usually the first choice for anxiety that shows up most days.

The First Few Weeks

Escitalopram’s FDA label is useful here because it reports side effects from generalized anxiety trials next to placebo rates:

• Nausea affected 18% of people on escitalopram versus 8% on placebo.
• Headache affected 24% versus 17%.
• Sleepiness affected 13% versus 7%, and insomnia 12% versus 6%.
• Fatigue affected 8% versus 2%.

The placebo column matters, because plenty of people taking a sugar pill reported headaches too. Our guide to Zoloft side effects in the first two weeks shows how one SSRI’s early effects compare with its long-term ones.

Side Effects That Can Last

Sexual side effects are the ones most likely to linger and the least likely to be mentioned. In the same trials, decreased libido affected 7% of people on escitalopram versus 2% on placebo, delayed ejaculation affected 14% of men versus 2%, and trouble reaching orgasm affected 6% of women versus less than 1%. The label adds that these figures probably underestimate the real rate because people often don’t raise the topic, and it tells prescribers to ask before and during treatment.

Weight change in escitalopram’s trials didn’t differ meaningfully from placebo, although the 2019 Lancet review lists weight gain among common problems with SSRIs and SNRIs as a group.

Rare but Serious Warnings

The label also carries warnings worth knowing:

• A boxed warning that antidepressants increased suicidal thoughts and behaviors in children and young adults in short-term studies, so people 24 and younger should be watched closely early on and after dose changes.
• Serotonin syndrome, a potentially life-threatening reaction that’s more likely when combined with other serotonergic drugs such as triptans or tramadol.
• A higher risk of bleeding with aspirin, NSAIDs, or blood thinners.
• Low blood sodium, especially in older adults, which can show up as headache, confusion, or unsteadiness.

Why Can Anxiety Feel Worse Before It Gets Better?

Some people feel more jittery, restless, or anxious in the first days of an SSRI, which is a cruel twist when anxiety is the reason you started. A 2009 systematic review of this early jitteriness found published rates ranging from 4% to 65% of people starting antidepressants, a spread that reflects how inconsistently it has been measured. Slower dose increases were a common response, though conclusive evidence for any strategy is lacking.

Early restlessness is worth reporting rather than quietly enduring or quitting, because your prescriber can adjust the starting dose or slow the pace of increases. Thoughts of self-harm need same-day help, as described below.

What Are the Side Effects of Buspirone?

Buspirone is FDA-approved for anxiety and works on serotonin 5-HT1A receptors rather than GABA, so it lacks the prominent sedation of benzodiazepines. Its trade-off is time: the 2020 review describes a gradual onset of around 10 days to 4 weeks, with doses two to three times a day.

In trials pooled in buspirone’s label, dizziness stood out at 12% versus 3% on placebo, followed by nausea at 8% versus 5%, headache at 6% versus 3%, and nervousness at 5% versus 1%. The label reports no evidence that buspirone causes tolerance or dependence, and it isn’t a controlled substance.

Two caveats are easy to miss. Buspirone won’t ease benzodiazepine withdrawal, because it doesn’t act on the receptors benzodiazepines use. And a Cochrane review summarized in the 2020 review found buspirone beat placebo for generalized anxiety, but with a smaller effect than benzodiazepines or antidepressants. Our Buspar side effects guide covers what to expect.

What Are the Side Effects of Hydroxyzine?

Hydroxyzine is an antihistamine with an FDA indication for anxiety symptoms, and its main appeal is speed. Its label says effects usually appear within 15 to 30 minutes, and its main side effects are drowsiness, which often fades within a few days, and dry mouth.

The label also lists limits that rarely make quick summaries:

• Its effectiveness for anxiety beyond 4 months hasn’t been assessed in systematic clinical studies.
• QT prolongation, a heart rhythm change, has been reported, mostly in people with other risk factors, and it shouldn’t be used if you already have a prolonged QT interval.
• It adds to the sedation of alcohol and other depressants.
• Older adults may become confused or oversedated, so they generally start on low doses.

A Cochrane analysis summarized in the 2020 review found hydroxyzine better than placebo and comparable to benzodiazepines and buspirone for generalized anxiety, though the studies carried a high risk of bias. Our hydroxyzine side effects guide covers everyday questions.

Why Are Benzodiazepines Prescribed Short Term?

Benzodiazepines such as alprazolam, clonazepam, and lorazepam bind to GABA receptors and slow brain activity, which is why they can calm a panic surge quickly. The FDA’s 2020 safety notice lists drowsiness, dizziness, weakness, and slowed breathing as common side effects, and it required an updated boxed warning for abuse, addiction, physical dependence, and withdrawal across the class.

The timeline surprises most people. Physical dependence can develop after several days to weeks of steady use, even as prescribed, and stopping abruptly can trigger withdrawal reactions that include seizures. The risks climb when benzodiazepines are combined with opioids or alcohol.

That’s why the 2020 review notes they’re no longer a first-line treatment on their own but can be used short term alongside an SSRI or SNRI, while also pointing out that strong evidence is lacking that SSRIs outperform them in the short term. The 2019 Lancet analysis found them effective but poorly tolerated. For adults 65 and older, the American Geriatrics Society’s 2023 Beers Criteria warn that all benzodiazepines increase the risk of cognitive impairment, delirium, falls, fractures, and car crashes.

What Happens When You Stop an Anxiety Medication?

Stopping is where many plans go wrong, usually because someone feels better, or worse, and quits without a plan.

For antidepressants, a 2024 discontinuation meta-analysis found that 31% of people who stopped an antidepressant had at least one discontinuation symptom, such as dizziness, headache, nausea, insomnia, or irritability, compared with 17% of people stopping a placebo. After accounting for that, the authors estimated that about 15% have symptoms caused directly by stopping and roughly 1 in 35 have severe symptoms, though some earlier reviews reported much higher rates. Escitalopram’s label recommends a gradual dose reduction, with a return to the previous dose if symptoms become intolerable.

For benzodiazepines, the FDA recommends a gradual, patient-specific taper and notes that some people have had withdrawal symptoms lasting many months.

Feeling better can also tempt people to stop early, yet the 2020 review notes that recommended treatment length ranges from 3 to 6 months to 1 to 2 years or longer. Our article on why people stop anxiety medication explores what drives that choice.

When Is a Side Effect an Emergency?

Most side effects are uncomfortable rather than dangerous, but a few need immediate help. Call 911 or go to an emergency room for any of these:

• Trouble breathing or extreme drowsiness, especially if a benzodiazepine was combined with opioids or alcohol
• A seizure
• Agitation, fever, heavy sweating, a racing heart, muscle twitching, or stiffness after starting or combining serotonergic medications, which can signal serotonin syndrome
• Fainting or an irregular heartbeat while taking hydroxyzine

If you’re having thoughts of harming yourself, call or text 988 to reach the Suicide and Crisis Lifeline. In an emergency, call 911.

For anything else that feels off, contact your prescriber rather than changing the dose yourself.

How Siggy Approaches Anxiety Medication Side Effects

When side effects start, many people feel like they’re on their own until the next appointment. That gap is where good medications get abandoned, and it’s the part of care Siggy takes seriously.

Siggy starts with a free, anonymous intake about your symptoms, health history, current medications, and past side effects, with no name, email, or account required. A licensed prescriber reviews everything before any treatment decision, and medication isn’t always the answer. Siggy’s medication care today centers on SSRIs for anxiety and depression, not controlled medications like benzodiazepines. If something feels urgent, safety escalation routes you to an in-house prescriber with the full conversation, so you don’t have to retell your story.

This article is for education only and isn’t a substitute for personal medical advice. It reflects sources available as of October 2026.

Plan for Side Effects Before Your First Dose

You deserve a medication plan built around what you can tolerate. Start your anonymous intake to share what you’ve tried and which side effects worry you, without giving your name or email. You’ll get a downloadable summary you can share, and a real doctor reviews everything before any treatment decision.