What to Expect in Your First 8 Weeks on an Antidepressant

Starting an antidepressant is a process that unfolds over weeks, not days. This guide explains what is normal, what to watch for, and when to call your care team.

How soon will I feel better?

Antidepressants work gradually. Some people notice small changes in the first 1–2 weeks, but meaningful improvement usually takes about 4–6 weeks, and the full benefit can take 8 weeks or longer. Sleep, energy, and appetite often improve before your mood does. Give the medicine time to work, even if you do not feel different right away.

What symptoms improve first?

Improvement is uneven. Sleep problems and low energy (fatigue) are often the slowest to get better and may linger the longest. Mood, interest, appetite, and concentration tend to improve over the first several weeks. Try not to judge whether the medicine isn't working too early.

Common early side effects

Side effects are most common in the first days to weeks and often fade as your body adjusts. These can include:

• Nausea, upset stomach, or diarrhea
• Headache
• Trouble sleeping or feeling sleepy
• Feeling jittery, restless, anxious, or "keyed up"
• Dry mouth
• Changes in sexual function or interest

Many of these ease within 1–2 weeks. Taking the medicine with food can help with nausea. Do not stop the medication on your own if a side effect appears — call your med provider first, unless a side effect feels unbearable or dangerous.

An important safety warning

Rarely, antidepressants can cause new or worsening thoughts of self-harm or suicide, especially in the first few weeks of treatment or after a dose change. This risk is higher in people under 25. This does not happen to most people, but it is important to know about.

Get help right away if you notice:

• New or worsening thoughts of death, self-harm, or suicide
• Sudden severe anxiety, agitation, panic, or restlessness
• Feeling unusually irritable, aggressive, or "wired"
• A sudden burst of energy or racing thoughts that feels unlike you

If you have thoughts of harming yourself, call or text 988 (Suicide and Crisis Lifeline) or call 911 or go to the nearest emergency room.

Take it consistently

Take your medicine every day as prescribed, at about the same time. It works best when taken steadily. Do not stop suddenly — stopping abruptly can cause withdrawal-like symptoms. If you want to stop, talk with your care team so they can guide you.

Follow-up matters

Plan to check in with your med provider early — often around 2 weeks after starting, and then regularly after that. These visits let your med management provider track your progress, adjust your dose if needed, and help with side effects. If you have had no improvement at all after about 4 weeks at a proper dose, your team may adjust the dose or consider a different medication.

When to call your med provider:

• Side effects that are not going away or are hard to tolerate
• No improvement after several weeks
• Any of the warning signs listed above (self-harm thoughts, severe agitation)
• Questions about your dose or how you are feeling

The bottom line

Be patient and stay in touch. Early side effects usually improve, benefits build over weeks, and close communication with your care team gives you the best chance of feeling better.