Lower numbers = closer to natural. Higher numbers = more enhanced.
Why this rating?
An antiplatelet and anti-inflammatory drug with no anabolic, androgenic or ergogenic action. It appears in this archive as the third component of the ECA fat-loss stack and as a cardiovascular consideration for long-term users. Does not move the natural ceiling. Rated 1 (basically natty).
Overview
Best known here as the "A" in the ECA stack, where it was traditionally included to prolong the thermogenic effect. Its more important role for this population is cardiovascular, though the guidance on taking it preventively has moved substantially, and taking it because you are "on cycle" is not a supported reason.
Important Warnings
- •GI bleeding is the dominant risk. Ranges from gastritis to significant gastrointestinal bleeding
- •Guidelines advise AGAINST initiating aspirin for primary prevention in older adults
- •Low-dose aspirin can diminish the effectiveness of topical minoxidil
- •Antiplatelet effect lasts 7-10 days. Disclose before any surgery
- •Tinnitus indicates toxicity, discontinue immediately
- •Never give to children with viral infections (Reye syndrome, 30-45% mortality)
- •Contraindicated in active peptic ulcer disease, hemophilia, G6PD deficiency and NSAID-associated bronchospasm
- •GI bleeding risk compounds with NSAIDs, corticosteroids, SSRIs and anticoagulants
Purpose & Use Cases
ECA Stack Component
The traditional third element alongside ephedrine and caffeine. Its inclusion is conventional in the classic protocol, and many modern users omit it given the GI bleeding risk relative to its marginal contribution.
Cardiovascular Secondary Prevention
Its evidence-backed use: 75-100mg daily for secondary prevention in people with established cardiovascular disease. Note that guidelines now advise AGAINST initiating aspirin for primary prevention in older adults because of bleeding risk.
Analgesic And Anti-Inflammatory
Standard use for pain and fever at 325-650mg every 4-6 hours, with a maximum of 4g/day.
Benefits
- Approximately 90% COX inhibition achieved with 160 to 325mg
- Antiplatelet effect persists 7-10 days from a single dose due to irreversible COX-1 inhibition
- Well-established secondary prevention benefit in cardiovascular disease at 75-100mg daily
- Effective analgesic and antipyretic
- Extremely cheap and universally available
- No hormonal action and no PCT implications
Good to Know
It can sabotage your minoxidil
Topical minoxidil is a prodrug that scalp sulfotransferase must activate. Low-dose aspirin inhibits sulfotransferase and can diminish topical minoxidil effectiveness. If you run both a daily aspirin and a hair protocol, they are working against each other.
The primary-prevention advice has reversed
Daily aspirin was once routine preventive advice. Guidelines now advise against initiating aspirin for primary prevention in older adults due to bleeding risk, reserving it for secondary prevention in people with established cardiovascular disease. "I take a baby aspirin because I'm on cycle" is not a supported rationale.
Irreversible means one dose lasts over a week
Aspirin permanently inactivates COX-1 in platelets, which cannot make more enzyme. The antiplatelet effect therefore lasts 7-10 days, the platelet lifespan, regardless of how fast the drug itself clears. This is why it must be disclosed well before any surgery.
Tinnitus is a toxicity signal
Ringing in the ears from aspirin indicates toxicity and warrants immediate discontinuation. Acute toxicity progresses from tinnitus, dizziness and lethargy to hyperthermia, respiratory alkalosis, high anion gap metabolic acidosis and seizures.
Dosage Guidelines
| Experience Level | Dosage Range |
|---|---|
| Beginner | 75 – 100 mg/day |
| Intermediate | 81 – 325 mg/day |
| Advanced | 325 – 650 mg/day |
Dosing depends entirely on purpose. Cardiovascular secondary prevention is 75-100mg daily ("baby aspirin"). Acute coronary syndrome loading is 162-325mg chewed, then 75-100mg daily. Pain and fever use 325-650mg every 4-6 hours to a maximum of 4g/day, and anti-inflammatory dosing is 2-4g daily in divided doses. In ECA stacks the aspirin component is conventionally around 325mg. Note the intermediate range spans these different purposes rather than representing a single escalating protocol, pick the dose that matches the reason you are taking it.
Peak plasma concentrations occur within 0.3 to 2 hours, but the pharmacologically meaningful duration is set by irreversibility rather than clearance, because aspirin permanently inactivates COX-1 in platelets, which cannot synthesise new enzyme, the antiplatelet effect persists for about 7 to 10 days, the lifespan of the platelet. Metabolism follows first-order kinetics at low doses and shifts to zero-order at high doses, which is why overdose escalates non-linearly.
Side Effects
Gastrointestinal irritation and bleeding
commonThe dominant risk, ranging from gastritis to gastrointestinal bleeding. This is why blanket preventive use has fallen out of favour, for many people the bleeding risk outweighs the benefit.
Take with food. Avoid combining with NSAIDs, corticosteroids or SSRIs, all of which raise GI bleeding risk. Do not use with active peptic ulcer disease or gastritis.
Intracranial hemorrhage
rareHigher risk in individuals with low BMI and in Asian populations.
A key reason primary prevention is no longer routinely recommended. Discuss with a physician before ongoing use.
Tinnitus
uncommonRinging in the ears indicates toxicity. This is a warning sign, not a nuisance effect.
Discontinue immediately if it occurs.
Hypersensitivity / aspirin-exacerbated respiratory disease
uncommonAERD (Samter triad), with an estimated prevalence of approximately 1% to 2%.
Contraindicated in anyone with a history of NSAID-associated bronchospasm or asthma of that type.
Reye syndrome (children)
rareA rare but potentially fatal condition with an estimated mortality rate of 30% to 45%, associated with aspirin use in children with viral infections.
Never give aspirin to children with viral infections.
General Mitigation Strategies
The central issue is bleeding, gastrointestinal above all, intracranial more rarely. This risk compounds with anything else affecting bleeding or gastric integrity, and NSAIDs, corticosteroids and SSRIs all add to it. In this population there is an additional specific consideration: many users already have elevated hematocrit and blood pressure from their cycle, which changes the risk calculus in both directions and is a genuine reason to involve a physician rather than self-prescribe.
Post Cycle Therapy (PCT)
No HPT axis interaction. No PCT implications.
How It Works
Aspirin irreversibly inhibits cyclooxygenase-1, abolishing its cyclooxygenase activity, and acetylates COX-2. Because platelets cannot synthesise new enzyme, inhibition of thromboxane A2 synthesis suppresses platelet aggregation for the platelet's entire 7-10 day lifespan. This irreversibility is what distinguishes it from reversible COX inhibitors like ibuprofen. Approximately 90% COX inhibition is achieved with 160 to 325mg.
Hormonal & Androgenic Profile
N/A: not an androgen.
Not a hormonal drug.
No 5-AR interaction, but there is an important and often-missed hair-protocol interaction: low-dose aspirin inhibits sulfotransferase, the enzyme that converts minoxidil into its active form, and can therefore diminish the effectiveness of topical minoxidil.
Antiplatelet. Protective in secondary prevention at 75-100mg daily, but guidelines now advise against initiating it for primary prevention in older adults because bleeding risk outweighs benefit.
Fundamentals
Reference on the practices relevant to Aspirin: how they are done and where they go wrong. Not a recommendation to use it.
Common Stacks
- Ephedrine + Caffeine + Aspirin: the classic ECA stack
- Low-dose aspirin for cardiovascular secondary prevention, under medical guidance
- Do NOT combine routinely with topical minoxidil. Aspirin can blunt its activation
Legal Status
Available over the counter worldwide. FDA-approved for a wide range of indications including acute coronary syndromes, myocardial infarction prophylaxis, stroke, pain, fever and inflammatory conditions.
Legal status varies by country and changes over time. This is a general summary, not legal advice.
WADA Status
Aspirin is not listed on the WADA Prohibited List and has no performance-enhancing action.