What to track on a peptide protocol

People using semaglutide, tirzepatide, or other GLP-1 class medicines often focus on the weekly injection and miss everything else that a consistent log can tell them. Real-world data shows that roughly two-thirds of people who start a GLP-1 receptor agonist for weight management discontinue within 12 months^[1]. Structured tracking does not fix every reason for stopping, but it does surface the side-effect and scheduling patterns that often precede dropout before they become the reason someone quits.

Why a protocol log matters

A 2011 systematic review of weight-management studies found a consistent positive association between self-monitoring of diet, activity, and weight, and weight-loss outcomes across the studies examined^[2]. More recently, a 2024 international review of GLP-1 adherence concluded that nutritional and lifestyle support, the kind a log makes visible, should be offered routinely rather than treated as optional, because pharmacotherapy alone is unlikely to sustain long-term obesity management^[3]. A log does not replace clinical follow-up. It gives you the data your clinician needs to adjust the protocol.

Dose and schedule: the minimum viable log

The first thing any tracking system should record is whether you actually administered each scheduled dose, on which date, at what time, and at what dose strength. This sounds obvious, and it is. It matters because GLP-1 and GIP receptor agonists are titrated over weeks or months, and missed doses can blur the picture of how your body is responding to a given strength.

Log the vial or pen lot number if you are using multi-dose vials. Log any dose you delayed by more than 24 hours. If you are tracking a peptide that requires reconstitution, note the reconstitution date and storage conditions. A vial opened six weeks ago and stored at room temperature is not the same as one prepared fresh.

Injection site rotation: why it belongs in the log

The prescribing information for tirzepatide (Mounjaro) specifies that the injection site should be rotated with each dose, across the abdomen, thigh, or upper arm^[4]. The reason is lipohypertrophy, a thickening of subcutaneous tissue at sites that are repeatedly injected. A study examining injection technique in insulin users found that before education, 51.4% of injections were administered into lipohypertrophic zones, and that figure dropped to 7.5% after structured rotation guidance was introduced^[2]. Injecting into a lipohypertrophic area changes absorption unpredictably.

A rotation log does not need to be complex. A simple sequence (left abdomen, right abdomen, left thigh, right thigh, repeat) noted alongside each dose entry is enough to prevent repeated use of the same site. Some people draw a rough body map and tick off quadrants. Either works as long as the record exists.

Side-effect monitoring: what to record and when

Gastrointestinal side effects are the leading clinical reason people discontinue GLP-1 class medicines. Nausea, vomiting, constipation, and diarrhoea are all dose-dependent and tend to peak in the first days after each dose escalation. Tracking the timing and severity of these events against the dose and schedule log lets you (and your prescriber) see whether the reaction is tied to escalation or whether it is persisting at a stable dose, which changes the clinical conversation.

The useful variables are: symptom type, onset time after injection, severity on a simple 1-10 scale, duration, and whether any dietary or behavioural change (smaller meals, more water, slower eating) appeared to help. You do not need a medical-grade instrument. A brief note on the same day the symptom occurs is more reliable than reconstruction a week later.

Body metrics and nutrition: what adds value

Weekly weight, recorded at the same time of day under the same conditions (typically morning, before eating), is the most reproducible body metric for most protocols. Body weight fluctuates several kilograms across a single day based on hydration and meals, so consistent measurement conditions matter more than precision equipment.

Protein intake is worth tracking if you are in a significant caloric deficit, because GLP-1 and GIP receptor agonists suppress appetite broadly and it is easy to under-eat protein while losing weight quickly. The international adherence review cited earlier flags lean mass loss during rapid weight loss as a specific nutritional concern in this population^[3]. You do not need a full dietary analysis, but a rough daily protein tally (total grams or servings) takes about two minutes.

Step count or another simple activity metric rounds out the useful minimum. These three variables (weekly weight, rough daily protein, step count) give a clinician enough context to distinguish between weight loss that is tracking the expected curve and a stall that warrants investigation.

What to do with what you record

A log that never gets reviewed is decoration. Build a short review into your routine: once a week, scan the prior seven days for patterns. Did you administer every dose? Were side effects clustered around a particular day or food? Is your weight moving in a direction consistent with the dose level?

Bring a summary to every clinical appointment. A clinician who can see three months of dose history, rotation sites, side-effect timing, and weight trend is in a different position from one working from memory. The per-country status of GLP-1 medicines, including what is and is not prescription-only in your jurisdiction, is covered on the semaglutide regulation page and the tirzepatide regulation page. Your prescriber is the right person to interpret the log and adjust the protocol.