Why Food Noise Comes Back on a GLP‑1 at the Same Dose

Food noise that comes back only in the last 2 or 3 days before each shot lines up with the weekly trough, when a GLP‑1’s level is lowest (Ozempic label; Mounjaro label). Noise on most days, even after a shot, suggests tolerance or a dose that is too low. After a late or missed shot, the likely cause is timing.

Key facts

• Semaglutide has a half-life of about 1 week; tirzepatide’s is about 5 days (Ozempic label; Mounjaro label).
• On a simple model, about 50% of the week’s peak is left on day 7 for semaglutide and 38% for tirzepatide (7 ÷ 5 = 1.4 half-lives).
• Steady levels take 4 weeks to build on tirzepatide and 4 to 5 weeks on semaglutide (Zepbound label; Ozempic label).
• A late shot can still be taken within 5 days on Ozempic and 4 days on Zepbound or Mounjaro (Ozempic label; Zepbound label).
• Daily semaglutide tablets peak about 1 hour after a dose, so they have no weekly trough (tablets label, section 12.3).

How to tell which cause you have

Wait until you have been on the same dose for a month. The level on a new dose keeps rising for 4 weeks on tirzepatide (Zepbound label, section 12.3) and 4 to 5 weeks on semaglutide (Ozempic label, section 12.3).

Then rate your food noise once a day from 0 (none) to 10 (constant), and note how many days it has been since your last injection. Keep it up for 2 to 4 weeks, so every day of the dosing week appears at least twice. Each cause leaves a different pattern in the scores.

If the noise never went quiet at all, especially on a starting dose, the drug may not have started suppressing appetite yet. The day of your dosing week for each score comes from your shot dates, which Pensday keeps for every shot you log.

The weekly trough

End-of-week hunger on Ozempic, or on any weekly GLP‑1, falls in the trough. Semaglutide peaks 1 to 3 days after a dose (Ozempic label, section 12.3), and tirzepatide at a median of 24 hours, within 8 to 72 hours (Zepbound label, section 12.3). From there the level falls until the next shot.

A simple model halves the level every 7 days for semaglutide and every 5 days for tirzepatide (Ozempic label, section 12.3; Mounjaro label, section 12.3). It ignores the rise in the first days after a shot, and gives these levels by day.

None of the four labels reports appetite by day of the dosing week, so the trough explanation comes from how the drugs are cleared. The curve models drug level rather than hunger, which is one of the limits of reading a GLP‑1 dose curve. Put your own shot dates into the GLP‑1 plotter to see this curve for your doses.

Exposure rises in proportion to the dose, so a higher dose raises the low point along with the peak (Zepbound label, section 12.3).

With daily semaglutide tablets, the level peaks about 1 hour after each tablet, so there is no weekly low to line up with (Rybelsus and Ozempic tablets label, section 12.3).

Tolerance at a stable dose

Tirzepatide slows stomach emptying most after the first dose, and that effect then "diminishes over time" (Zepbound label, section 12.2).

For appetite, the evidence is on semaglutide 2.4 mg. In STEP 5, it beat placebo on hunger and fullness only at week 20, while control of cravings stayed better through week 104 (Wharton et al., 2023). Those who answered that questionnaire had lost 14.8% of their weight on semaglutide and 2.4% on placebo by week 104.

A 60-week trial in 120 adults found hunger and food preoccupation lower than on placebo at week 20 but no different at weeks 40 and 60 (Tronieri et al., 2026). People on semaglutide still ate 240 to 292 kcal less at a lunch where they could eat freely, at all three visits.

The labels tell prescribers to "consider treatment response and tolerability" when choosing the maintenance dose (Zepbound label, section 2.1; Wegovy label, section 2.2). On Mounjaro, the UK label allows a step up from 5 mg to 7.5 mg after at least 4 weeks, if needed (Mounjaro SmPC, section 4.2).

Late or missed doses

A shot taken 2 days late moves that week’s trough 2 days later, and a skipped shot lets the level keep falling for another week. Ozempic lets you take a late dose within 5 days of the missed day, Zepbound and Mounjaro within 4, and past that window the dose is skipped (Ozempic label, section 2.1; Zepbound label, section 2.3). Wegovy’s missed-dose rule depends on when the next dose is due.

Sugar cravings on semaglutide

In a phase 1 trial, semaglutide 2.4 mg cut energy intake at a free-choice meal by 35% against placebo after 20 weeks (Wegovy SmPC, section 5.1). People also reported less desire for sweet food.

In STEP 5 the advantage on sweet cravings held at weeks 20 and 52 (Wharton et al., 2023). At week 104, the UK label says "no clear effect was seen for craving of sweet food", while control of cravings and savory cravings still favored semaglutide (Wegovy SmPC, section 5.1). Sweet cravings coming back in the second year, while other cravings stay quiet, match that result.

For tirzepatide, the UK label reports lower craving for "fast-food fats, and sweets, carbohydrates and starches" against placebo, with no two-year result (Mounjaro SmPC, section 5.1). Craving for alcohol has its own trials of semaglutide in alcohol use disorder.

What food noise is

A 2025 paper proposed a formal definition: "persistent thoughts about food that are perceived by the individual as being unwanted and/or dysphoric" (Dhurandhar et al., 2025). The authors separate it from ordinary thoughts about meals by its intensity and intrusiveness, and have begun validating a questionnaire to measure it.