How the stack check works — and how we work
A free educational reference for adults covering 200 substances. You pick substances; the tool shows what the combination is used for, which side effects are possible, what may lower the risks, and which check-ups and blood tests to do. Every sentence comes from a knowledge base built from medical sources — nothing is generated on the fly.
What the tool does
Every report and every substance page answers four questions, always in the same order.
What it gives
The effects people use each substance for and what the sources report — with strength (mild, clear, strong), what each substance adds, and which of the effects matter for the goal you choose.
Possible side effects
Which side effects are possible, how often they are reported and how to notice them early. Calmly: possible does not mean certain, and most changes can be spotted in time.
How to lower the risks
For each side effect: everyday measures, supplements with some evidence, and options a doctor may consider — always marked “only if a doctor prescribes”. They may lower the chance; none removes the risk.
Check-ups and blood tests
Which tests and check-ups to do — baseline, while taking, after stopping and every year — and which doctors can help. For extreme-risk substances there is no schedule: no testing makes them safe.
How levels are worked out
Each possible side effect gets one of four levels. They are general categories from the literature for a substance or a combination — not a personal risk.
- Base level
Every substance in the knowledge base has a level for each side effect it can cause, taken from the sources. For a combination, the starting point is the highest level among the substances you picked.
- Adding up
When several substances can cause the same side effect, it adds up: two moderate sources raise it one step (at most to “Elevated”), two serious ones can raise it further. Some side effects have a ceiling they never go above.
- Combinations
Some pairs are known to interact — one makes a side effect of the other more likely or stronger. These combination rules can raise a level, and the report says which pair did it and why.
- Overall profile
All levels are combined into a profile score from 0 to 100. A single side effect at “High” puts the whole profile in the high band; two serious ones at “Elevated” put it at least in the elevated band. The profile is never higher than the worst single risk. Research chemicals and substances with animal data only start at “Moderate”: unknown human safety is not a low risk. A stack with an extreme-risk substance is always at the top.
- For women
Some side effects carry a higher level for women — virilization, for example. If you choose “Show for: Women” in the stack check, those levels are used; otherwise the pages show both.
The four levels
Level: general category from the literature, not your personal risk
Profile bands (score 0–100)
What we never do
We never say how much, how often or for how long to take anything.
We don’t say where to buy any substance and we don’t sell them. Nothing is sold in the reference.
The reference will not help anyone pass a doping test.
We don’t ask about health and don’t assess personal risk. Only a doctor who knows the person can do that.
No registration, no cookies, no advertising or third-party analytics services. The stack you build is stored only in your browser: in the page address after the # sign (the browser does not send this part to the server) and in the memory of this tab. A language you choose by hand is remembered in this browser. Your age confirmation is kept in the memory of the tab until you close it.
We only count events — a report opened, a link sent, a page printed — by the name and language of the page, without the stack.
To stop bots from inflating the counters, the server immediately replaces your IP address with a salted hash and deletes the hash within one hour at the latest. We do not record the IP address itself. Under data-protection law such a hash still counts as personal data. We process it on the basis of legitimate interest — protecting the statistics from abuse.
Sources we use
Each substance page lists the specific sources behind it. The main ones:
How the knowledge base was prepared
Medical review: [full name], [specialty], reviewed knowledge base version 2026-10-07-157b0a06 of [date]. The review confirms the accuracy of the information and is not a recommendation to use any substance.
The substance descriptions, levels and ways to lower the risks were drafted with AI assistance from the sources listed here.
The knowledge base was then checked by a physician; the review record is shown above.
Levels and texts are updated as new evidence appears. If you spot a mistake, please tell us.
Disclaimer
This is an educational reference for adults (18+). It is not medical advice, not a diagnosis, not a medical device and not a tool for assessing personal risk. It does not recommend or encourage using any substance. The safest choice is not to use them.
The reference describes substances and combinations in general terms, based on published sources. Levels are general categories for a combination, not anyone’s personal risk: how a body reacts depends on many things the reference does not know. Information may become outdated; the date and version of the knowledge base are shown on the page.
Many substances listed are prescription-only, controlled by law or not authorised for human use. Buying, possessing, importing or using them may be illegal where you live. Check your local law. The reference does not help anyone obtain any substance.
Prescription medicines named as a way to lower a risk are only for a doctor to decide on, based on test results. Do not take them on your own: they have side effects of their own.
Warning signs listed on the pages need urgent medical help: chest pain, sudden shortness of breath, a sudden severe headache, yellowing of the skin or eyes and others. The reference is not meant for emergencies. In an emergency, call your local emergency number.
If you use or are thinking of using any of these substances, talk to a doctor and be honest about everything you take: it determines which tests and treatments are safe.
The reference is provided free of charge and as is. We try to keep the information accurate but do not guarantee that it is complete or up to date. To the extent permitted by applicable law, we are not liable for decisions made on the basis of it. Nothing here limits liability that the law does not allow to be limited.
Tested sport
Competing in a federation with doping control? Most substances here are prohibited: anabolic agents, SARMs, growth hormone and other peptide hormones, aromatase inhibitors, SERMs, insulin and diuretics. The WADA Prohibited List is updated every year — check the current version. The reference gives no detection times and will not help anyone pass a test.