How to Track Side Effects in Your First 90 Days on Finasteride (Free Log)

By the Finasteride Fast editorial team · researched from published studies and FDA labeling; not reviewed by a clinician

Most worry about finasteride side effects happens in the first few months, usually without any record to check it against. A short weekly log fixes that.

Short answer: start a week before your first tablet. Rate a handful of things on a 0 to 10 scale (sex drive, erections, ejaculation, mood, sleep, energy, breast tenderness), and then repeat the same ratings once a week for 90 days. Write down life events next to the numbers. That baseline is what lets you and your prescriber tell a real change from the normal ups and downs everyone has, and from symptoms that are driven partly by worry. The log is below; copy it into a notes app or spreadsheet, or print this page.

Why a baseline matters so much

Finasteride's clinical trials show something people rarely hear: the placebo group reported many of the same side effects. In the three 12-month trials behind Propecia, 945 men took finasteride 1 mg and 934 took a placebo. Here are the drug-related sexual adverse experiences reported:

Two things follow. Finasteride does cause a small excess of these effects, and the label lists them. But a meaningful share of men who notice these changes would have noticed them anyway. Without a "before" record you can't tell which group you're in. Expectation also shapes what people notice and report, an effect called nocebo. Our nocebo article covers the research. A log doesn't make real symptoms disappear. It makes them visible and dated, which is what a prescriber needs.

The 90-day log

Rate each item from 0 (worst or none) to 10 (best or normal for you). For breast tenderness, use 0 for none and 10 for severe. Fill it in on the same day each week, at a similar time.

Weekly for the first month catches early changes. Every two weeks after that is enough for most people. Keep the "life events" column honest: alcohol, a bad week at work, poor sleep, a new partner, an argument, illness, travel, a new supplement or medication. Those explain a lot of week-to-week movement.

Optional extras

• Missed doses: a tick for each day taken, so you can see whether a change follows a gap or a restart.
• Other medications: especially anything for mood, blood pressure, or erections, and any oral minoxidil.
• Hair photos: monthly, in the same light and angle. See photographing progress correctly.

Setting it up in five minutes

1. Pick one place. A notes app, a spreadsheet, or a printed copy of this page. Use the same one for 90 days.
2. Set a weekly reminder on your phone for the same day and time. Sunday evening works for many people because it's after the weekend.
3. Do the baseline honestly. Rate how things actually are, not how you'd like them to be. If something is already a problem before you start, that's important information.
4. Keep ratings quick. Thirty seconds per item. Overthinking each number makes logging a chore, and you'll stop.
5. Write one line of notes every time, even if it's "normal week."

An illustrative entry

This is a made-up example to show the format, not a real person's results. Baseline: sex drive 7, erections 8, mood 7, sleep 6, energy 6. Week 3: sex drive 5, erections 7, mood 6, sleep 4, energy 5. Notes: "Two late nights for a work deadline, more drinks than usual Saturday." Week 4: sex drive 7, erections 8, mood 7, sleep 6. Notes: "Normal week." Read together, that dip looks like a rough week rather than a drug effect. Had the numbers stayed down for several readings with nothing in the notes, it would be worth a call.

Reading your log: signal or noise?

Noise doesn't mean "ignore it." It means bring the whole log, not a single bad week, to the conversation. For context on the full range of reported effects, see finasteride side effects by the numbers and our review of sexual side effects.

What to bring to your prescriber

1. The log, including the baseline week
2. When you started, any missed doses, and any change in dose or product
3. Everything else you take, including supplements and topicals
4. The specific change that worries you, when it started, and whether it's constant or comes and goes
5. What you'd like to happen: reassurance, a dose or format discussion, a pause, tests, or stopping

Decisions about dose, format (oral or topical), pausing or stopping belong to you and your prescriber together. Don't change your regimen based on a log alone. The patient leaflet's own instruction is to tell your healthcare provider about any side effect that bothers you or doesn't go away. Your log turns that into a useful conversation.

Things the log won't settle on its own

• Hair results. The label says daily use for three months or more is generally needed before benefit appears. Day 90 is a side-effect checkpoint, not a verdict on your hair. Our 6-month assessment guide covers judging results.
• Mood. Track it, but take any sustained low mood straight to your prescriber. See finasteride and mood.
• Symptoms after stopping. The label lists postmarketing reports of sexual dysfunction that continued after stopping. If symptoms persist after you stop, keep logging and keep your prescriber informed.

Privacy and who sees it

This log contains sensitive information, so keep it somewhere private: a locked notes app, or paper at home rather than a shared work drive. You choose who sees it. Many men find it helpful to share the mood and energy columns with a partner, who may notice changes before they do. The sexual-function columns can stay between you and your prescriber. If you use a telehealth service, check how its messaging works so you can send a photo of the log or type in the numbers. Don't post it on forums expecting a diagnosis. Strangers can't see your history, and a thread full of worst-case stories is the fastest way to turn noise into worry.

After day 90

If everything is stable, switch to a quick monthly check-in for the rest of the first year, then whenever something changes, such as a new medication, a dose change, or a switch between oral and topical. Keep the baseline row. It's the most valuable line in the whole log, and you can't recreate it later.

The free hair-loss treatment guide below covers finasteride, minoxidil and combination approaches, with realistic timelines. It pairs well with this log if you're just starting out.

When to see a doctor: contact your prescriber about any side effect that bothers you or persists, any breast lump or discharge, or sustained low mood. If you have thoughts of self-harm, call or text 988 in the US or your local emergency number.