If you have a medical cannabis prescription in the UK, tracking your use is one of the most practical things you can do. It helps you prepare for clinic consultations, manage your stock across multiple products, and understand what is working for you. But knowing what to track — and how — can be confusing when you are starting out.
Why track your medical cannabis use?
There are three main reasons patients track their usage:
Clinic consultations. Your prescribing clinic will want to know how you are getting on with your treatment. Having actual data, rather than a vague sense of "I think I used about half," makes these conversations much more productive. You can discuss strain effectiveness, dosage patterns, and any side effects with confidence.
Prescription management. Medical cannabis prescriptions in the UK are dispensed in specific quantities, and you are expected to stay within your prescribed pace. Tracking helps you know whether you are on track, running ahead, or likely to run out before your next prescription date. This matters for continuity of care — running out early means gaps in your treatment.
Personal insight. Over time, patterns emerge. You might notice that a particular strain works better at certain times of day, that your usage has changed over weeks, or that specific methods produce more consistent effects. These insights are genuinely useful — but they only appear when you have a record to look back on.
What to track
The short answer: the more you record, the more insight you get. But even basic tracking is better than none. Here is what most patients find useful to log:
- Date and time. When you took each dose.
- Strain or product name. Which product you used. If you have multiple products, this is essential.
- Amount. How much you used, ideally in grams. Even an estimate helps.
- Method of consumption. Vape, oil, flower, etc. Different methods have different onset times and durations.
- Effects and notes. How you felt afterwards. Did it help with the symptom you were targeting? Any side effects?
- Mood and sleep. Optional but helpful, tracking mood and sleep alongside consumption can reveal patterns over weeks.
You do not need to track all of these from day one. Start with strain, amount, and method (the essentials for stock management) and add effects and notes as you get into the habit.
Methods of tracking: pros and cons
Spreadsheet
Spreadsheets are the most common starting point. They are free, customisable, and private if stored locally. You can set them up exactly how you want, with columns for everything you care about.
But spreadsheets have real downsides. They require manual entry every time: you have to remember to open the file and fill in the row. Adding up totals, calculating burn rate, and working out run-out dates means writing formulas. Spotting trends means building charts. And spreadsheets are not designed for quick logging on a phone.
Notebook or paper diary
A paper diary is simple, private, and never runs out of battery. There is something satisfying about a physical record. But paper cannot do maths; you have to add up totals yourself. You cannot search or filter your history. And there is no backup if the notebook is lost or damaged.
Tracking app
Apps like Grams Left automate the hard parts. Every dose updates your stock balance, burn rate, and estimated run-out date, with no formulas needed. A prescription countdown tells you at a glance whether you are on track. Charts and trends emerge automatically from your data. And logging takes seconds on your phone, even offline.
The trade-off is that an app is digital: it requires a device and, for cloud features, an internet connection. But for most patients, the convenience and automation outweigh this.
Which method should you choose?
Start with whatever gets you tracking consistently. A spreadsheet you actually use is better than an app you ignore. A notebook on the kitchen counter is better than a perfect system that never gets opened.
If you find yourself frustrated with the manual work (adding up totals, wondering when you will run out, forgetting to log), that is when an app becomes valuable. The goal is not the tool; it is the habit of tracking, and the insight that comes from it.
Grams Left is free for the core tracker, with no card required. If you are curious, you can start tracking free and see whether it fits your routine.
Whatever method you choose, the most important step is the first one: start logging. Your future self, and your clinician, will thank you.