# Supplements and medicines: log them as interventions

A dose with its time annotates your record; the regimen builder and the interaction check start from the log; nothing here is a recommendation to take anything.

Type: practice · Domain: Activities & Lifestyle · Accuracy: Self-reported · Importance: Core

Also called: supplement tracker, supplement log, medicines, medication log, regimen builder, interaction check, polypharmacy, creatine, biotin, dose and time, what to log, new supplement

## Do this

- Log every supplement as a dose with its time and amount, and list your medicines by name, from the master list or as your own entry, and keep the name the same so the history lines up.
- Log a change, a new one, a dose change, a stop, on the day it happens.
- Before a blood draw, keep taking everything, record it, and pause high-dose biotin for three days.
- VT uses the medicine list for the interaction check and does not log medicine doses; nothing in VT changes a prescription, and no entry on this site is a recommendation to take anything.
- Plan a supplement set with Eir in the regimen builder, and run the interaction check, on paid plans, before adding to it.

## Why a dose with its time

A dated dose annotates the record, and the annotation is how a change gets its explanation: magnesium at night beside overnight heart rate variability, a stimulant beside the next night's resting heart rate, melatonin beside sleep timing, creatine beside creatinine, a new lipid-lowering medicine beside the lipid panel. Logged, the change is an intervention you can read on your own record, the way a protocol is; unlogged, it looks like a change in you to anyone reading the record, Eir included. VT's engines do not read the supplement log yet.

## Why medicines too

The laboratory entries depend on it. Creatine raises serum creatinine without changing kidney function, so the creatinine-based kidney estimate reads lower and PhenoAge reads older than they are (Gualano 2008); high-dose biotin interfered with nine of 23 biotinylated assays in a test of six adults taking 10 mg a day, among them thyroid, vitamin D and ferritin tests (Li 2017); metformin lowered vitamin B12 by 19 percent over four years in a randomized trial of 390 people (de Jager 2010). VT shows the creatine note beside creatinine, the biotin rule before a draw and the metformin note beside B12 only when the log holds them. The pre-visit report lists what you take beside the results, and the interaction check reads your medicines alongside your supplements.

## What the tools are

The supplement tracker, free on every plan: the log, the master list, your own entries, and the dose history on every day. The regimen builder, with Eir: a proposed set built from your labs, your biomarkers and your goal, with every claim screened through Diet-MisRAT and each addition checked against the rest of what you take; the review is once a month on Standard and unlimited on Premium. The interaction check, on paid plans: each supplement checked against your other supplements and your medicines in the Examine safety database, with the reference shown.

## What this is not

Advice to take anything. The evidence grade Eir shows beside a claim says how strong the claim is, and most supplement claims are weak; the log exists so that whatever you decide, with your doctor where a medicine is involved, is readable afterwards on your own record.

Vitality Tracker describes and tracks your measures against your own history, for general wellness and for discussion with a health professional. It does not diagnose, predict or monitor any disease, and it does not recommend, start or stop any supplement or medicine.

## Sources

1. Gualano B, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol 2008;103:33–40. [doi:10.1007/s00421-007-0669-3](https://doi.org/10.1007/s00421-007-0669-3)
2. Li D, et al. Association of biotin ingestion with performance of hormone and nonhormone assays in healthy adults. JAMA 2017;318:1150–60. [doi:10.1001/jama.2017.13705](https://doi.org/10.1001/jama.2017.13705)
3. de Jager J, et al. Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ 2010;340:c2181. [doi:10.1136/bmj.c2181](https://doi.org/10.1136/bmj.c2181)
4. Vitality Tracker, Plans and pricing (the tracker, the regimen review and the interaction check by plan); the engine catalogue of 15 October 2026 (the supplement record); Recommended baseline lab panel v0.1 (the pre-draw rules).

## Related

- [Protocols: log the things you do to yourself](https://vitalitytracker.app/knowledge/protocols-how-to)
- [What Eir can do, and what it won't](https://vitalitytracker.app/knowledge/what-eir-can-do)
- [Getting your blood tests done in New Zealand](https://vitalitytracker.app/knowledge/blood-tests-in-new-zealand)
- [Renal function and electrolytes](https://vitalitytracker.app/knowledge/renal-function-and-electrolytes)
- [Vitamin B12 and folate](https://vitalitytracker.app/knowledge/vitamin-b12-and-folate)
- [TSH](https://vitalitytracker.app/knowledge/tsh)
- [Overnight heart rate variability](https://vitalitytracker.app/knowledge/overnight-hrv)

Reviewed October 2026 · v1

Source: https://vitalitytracker.app/knowledge/supplements-and-medicines-as-interventions