What a clenbuterol cycle means
The source discussions date from 2003 to 2018. A proposed plan records what a member intended to do; a personal account describes what that person says happened. Reposted guides can repeat the same figures without adding independent evidence.
Clenbuterol is not FDA-approved for human use in the United States, and no safe or effective bodybuilding or weight-loss cycle has been established. The schedules discussed here are descriptions of what forum users published, not medically validated dosing instructions. Serious heart and electrolyte complications have been reported.
How the published cycles compare
Most short plans increase the amount during the first several days. Some then hold it steady, while others reduce it near the end. A separate group alternates weeks of use and non-use. Neither the length of a cycle nor the inclusion of breaks establishes its safety.
| Published example | Length | Main pattern | Original discussion |
|---|---|---|---|
| First-cycle handbook (2003) | 14 days | Daily increases, a longer middle phase, then a reduction | EliteFitness |
| Repeat-cycle handbook (2003) | 14 days | Same outline, with higher amounts than the first example | EliteFitness |
| SportWiki | 14 days | Daily increases, a middle phase, then lower amounts at the end | SportWiki |
| First-cycle proposal (2014) | 14 days | Stepwise increase followed by a multi-stage decrease | AnabolicMinds |
| Split-dose proposal (2013) | 14 days | Three daily administrations described in the original post | EliteFitness |
| Dutch forum proposal (2013) | 14 days on, 14 off | Four increasing stages before a two-week break | Bodybuilding.nl |
| Dutch forum response (2016) | 14 days on, 14 off | Five increasing stages, presented as a reply | Bodybuilding.nl |
| Personal plan (2012) | 21 days | Three-stage increase, followed by a reduction | AnabolicMinds |
| Personal plan (2014) | 21 days | Several days at each level, then a gradual decrease | AnabolicMinds |
| Repeated cycle (2016) | 10-week sequence | Three 2-week periods of use separated by two-week breaks | EliteFitness |
| Combined cutting account (2018) | About 6 weeks | Part of a longer multi-substance account | Forumoretesto |
A calendar with 14 days of use and 14 days off spans 28 days, not 28 days of continuous exposure.
14-day clenbuterol cycles
Two-week schedules recur throughout the older discussions collected here. Their opening phases, middle periods and endings differ. The amounts are historical forum reports, not established starting amounts, targets or safety limits.
First and repeat cycles from the BigAndy69 FAQ
One of the oldest and most widely circulated guides appeared on EliteFitness in February 2003. It includes separate first-cycle and subsequent-cycle examples. Both increase over several days, hold a higher amount during the middle of the cycle and reduce the amount over the final two days.
| Days | First-cycle example, mcg/day | Repeat-cycle example, mcg/day |
|---|---|---|
| 1 | 20 | 60 |
| 2 | 40 | 80 |
| 3 | 60 | 80 |
| 4 | 80 | 100 |
| 5 | 80 | 100 |
| 6-12 | 100 | 120 |
| 13 | 80 | 100 |
| 14 | 60 | 80 |
The repeat-cycle figures come from the same author. They are not evidence that later cycles become safer or more effective.
Versions of this FAQ also appear on AnabolicMinds and MuscleChemistry. Their matching schedules do not represent independent experiences.
Original post: BigAndy69, EliteFitness, February 6, 2003
The SportWiki short cycle
SportWiki publishes another two-week pattern. It resembles the old FAQ, but the amounts do not match: the rise continues for an additional day, the middle phase is higher, and the final day is lower. The differences show why the label "two-week cycle" does not identify one consistent schedule.
| Days | Amount shown in the article, mcg/day |
|---|---|
| 1 | 20 |
| 2 | 40 |
| 3 | 60 |
| 4 | 80 |
| 5 | 100 |
| 6-12 | 120 |
| 13 | 80 |
| 14 | 40 |
A first-cycle proposal with a reduction in the second week
An AnabolicMinds member using the name JiveTurkey2 published a proposed first cycle while trying to lose abdominal fat. Unlike the older FAQ, this plan begins reducing the amount before the final days. The thread contains conflicting replies: one member accepts the plan while another suggests a higher amount and questions the need for a reduction.
| Days | Proposed amount, mcg/day |
|---|---|
| 1-2 | 20 |
| 3-4 | 40 |
| 5-6 | 60 |
| 7-9 | 80 |
| 10-12 | 40 |
| 13-14 | 20 |
| 15-28 | No use in the proposed calendar |
Source: JiveTurkey2 - Clenbuterol Cycle - Need Criticism, AnabolicMinds
A split-dose proposal on EliteFitness
In this discussion, a forum member named michto describes a schedule split between morning, midday and evening. That differs from the single daily totals shown in many other threads. Several replies argue that the health risks outweigh the expected body-composition benefits.
| Days | Morning, mcg | Midday, mcg | Evening, mcg | Daily total, mcg |
|---|---|---|---|---|
| 1-2 | 20 | 20 | 20 | 60 |
| 3-4 | 40 | 20 | 20 | 80 |
| 5-6 | 40 | 40 | 20 | 100 |
| 7-9 | 40 | 40 | 40 | 120 |
| 10-14 | 60 | 40 | 40 | 140 |
The reported daily total combines the three administrations described in the post.
Source: michto - The Best Way to Use Clenbuterol, EliteFitness
Two different schedules from Bodybuilding.nl
The March 2013 thread begins with a proposed four-stage schedule followed by two weeks without use. The author intends to start again on day 29. Another thread, from January 2016, contains a five-stage proposal in a reply. They are separate posts by different people, with different starting amounts and different increases.
March 2013 proposal
| Days | Reported amount, mcg/day |
|---|---|
| 1-3 | 50 |
| 4-6 | 75 |
| 7-10 | 100 |
| 11-14 | 125 |
| 15-28 | None |
| 29 | Planned restart |
Source: Thomas G - Bodybuilding.nl
January 2016 forum reply
| Days | Reported amount, mcg/day |
|---|---|
| 1-3 | 25 |
| 4-6 | 50 |
| 7-9 | 75 |
| 10-12 | 100 |
| 13-14 | 125 |
| 15-28 | Described as a break |
Source: GewoonDenny - Bodybuilding.nl
Replies in the 2013 thread include skepticism about whether the drug is necessary at all. In the 2016 thread, another member says that personal experiences have been less impressive than the claims commonly made about cutting results.
21-day clenbuterol cycles
Three-week plans extend exposure beyond the common 14-day period. Some writers describe a steady increase followed by a reduction; others hold a higher amount for a longer middle phase. The added week has not been shown to make a cycle safer or more effective for fat loss.
The AZ JB plan on AnabolicMinds
AZ JB posted a three-week schedule intended for his girlfriend. It begins with several days at each level, includes a longer central stage and falls again before day 21. The initial message also described supplement use, while responses disagreed about whether a reduction at the end made sense. The thread is a discussion of a proposal, not a documented successful course.
| Days | Proposed amount, mcg/day |
|---|---|
| 1-3 | 20 |
| 4-7 | 40 |
| 8-14 | 80 |
| 15-17 | 40 |
| 18-21 | 20 |
Source: AZ JB - Clenbuterol Cycle, AnabolicMinds, April 2012
A second three-week plan with a longer middle stage
In a later AnabolicMinds thread, the user aktiv posts a 21-day plan while asking how much weight might be lost. Compared with AZ JB's schedule, this one starts higher, maintains its middle level for seven days, and steps down during the final week. The replies emphasize that body-weight changes also depend heavily on eating habits and training.
| Days | Proposed amount, mcg/day |
|---|---|
| 1-3 | 60 |
| 4-7 | 80 |
| 8-14 | 100 |
| 15-18 | 80 |
| 19-21 | 60 |
A cycle followed by a thyroid-hormone phase
Another AnabolicMinds member described three weeks of clenbuterol, a three-week break and plans for a subsequent cycle involving T3, a thyroid hormone. The message assigns clenbuterol levels to days 1-3, 4-7, 7-14, 15-18 and 19-21. Day 7 appears in two different stages in the original post, so the timetable is internally inconsistent. Replies then propose different ways of combining or separating the substances.
Thyroid-hormone combinations introduce additional medical risks and are not a proven way to make a clenbuterol cycle safe. The original post does not establish that the proposed combination was completed or produced the claimed body-composition changes.
On/off schedules and longer courses
Two weeks on, two weeks off
A repeated pattern discussed on EliteFitness in October 2016 consists of two weeks of use, two weeks off, then another two-week period of use. The author describes three such periods, with two breaks between them. That makes a 10-week timeline containing six weeks of reported use, not a continuous 10-week course. The member asks how much time should pass before another cycle.
| Weeks | Pattern in the 2016 post |
|---|---|
| 1-2 | Use |
| 3-4 | Break |
| 5-6 | Use |
| 7-8 | Break |
| 9-10 | Use |
Source: 3dwin - Off Time Between Clen Cycles, EliteFitness
Two days on, two days off
An EliteFitness article from August 2014 also mentions alternating two-day periods and a three-weeks-on, three-weeks-off format. These are different calendar patterns, not established medical protocols. A short break does not mean the drug has cleared from the body; toxic effects can persist well after the last exposure.
Source: EliteFitness - Clenbuterol, August 2014
A six-week cutting account involving other substances
A 2018 Russian-language post on Forumoretesto describes a cutting period involving clenbuterol and stanozolol, with ketotifen added in part of the account. Its clenbuterol portion is described as half a tablet twice daily on days 8-11, one tablet twice daily on days 12-23, and one and a half tablets twice daily on days 24-36. The account does not identify tablet strength, so its tablet fractions cannot be reliably converted to micrograms.
This is not a clenbuterol-only cycle. Because several substances are involved and the outcome is self-reported, there is no way to isolate which substance, dietary changes or training changes accounted for the described results. The author's claim that correct use can be safe is not supported by toxicology evidence.
Source: Edik - Personal Experience with Sports Pharmacology, Forumoretesto, January 2018
Why the schedules disagree
Increasing and reducing the amount
The BigAndy69 guide, SportWiki and several independent threads show increases at the beginning, but they differ on how long higher amounts are maintained. Some users lower the amount during the final days. Others argue that doing so has no purpose. Neither position is backed by a validated weight-loss treatment protocol.
Dividing the daily amount
One 2013 EliteFitness post divides the amount between three administrations. Other threads show only daily totals. Dividing an amount does not make the total exposure less hazardous, and the forum comments do not establish which pattern, if any, would be medically acceptable.
Repeated use and tolerance
Some posts attribute a reduced perceived effect to tolerance and respond by proposing larger amounts or a break. Less shaking or a weaker subjective effect is not proof that the cardiovascular risks have declined.
Combinations with other drugs
The older discussions mention thyroid hormones, other stimulants, antihistamines and anabolic agents. Such combinations complicate the picture: if someone reports a change in weight or develops symptoms, it may be impossible to determine which substance was responsible.
The BigAndy69 material on EliteFitness was also circulated as a "handbook" on AnabolicMinds and later republished on MuscleChemistry. Similar wording and identical daily figures point to the same underlying text. Finding it on three websites does not mean three different people independently completed the course.
What about fat loss and muscle preservation?
Clenbuterol activates beta2-adrenergic receptors and affects metabolism and skeletal muscle. Human trials have also examined lean tissue and strength, as summarized in the human-trial comparison. Those experiments do not validate the forum schedules collected here. Personal weight-loss reports usually lack the measurements and controls needed to separate drug effects from diet and training.
That distinction matters when a poster reports progress during a cut. Body weight includes water, glycogen, fat and lean tissue. Without consistent measurements, the number on a scale alone cannot show how much fat was lost.
Side effects and health risks
Clenbuterol is used as a bronchodilator in some countries but is not approved for human use by the US FDA. Poison Control describes tremor, a rapid heart rate, anxiety, low blood potassium, high blood glucose and potentially serious heart problems. The substance can remain active long enough for effects to persist beyond the day it was taken.
What poisoning reports show
In a 2014 study based on 63 clenbuterol exposure reports to the New South Wales Poisons Information Centre, at least 53 people were hospitalized. The recorded cases included rapid heart rate, gastrointestinal symptoms, tremor and one cardiac arrest. These were reported exposure cases, so the hospital admission proportion must not be interpreted as the risk among all users.
A separate descriptive study reported prolonged symptoms and evidence of heart muscle injury in two patients. Neither report identifies a harmless bodybuilding dose or validates a forum cycling schedule.
Symptoms that need urgent attention
Chest pain, fainting, an irregular or very rapid heartbeat, seizures, severe weakness or difficulty breathing warrant urgent medical assessment. In the United States, Poison Control can be reached at 1-800-222-1222, and emergency symptoms require emergency services.
Use in competitive sport
Clenbuterol is prohibited in competitive sport under the WADA Prohibited List. Taking breaks or using smaller amounts does not create an exemption from anti-doping rules.
Medical sources: Poison Control | Brett et al., 2014 | Spiller et al., 2013 | USADA
Frequently asked questions
What is a clenbuterol cycle?
It is a period during which someone uses clenbuterol, sometimes followed by a planned break. Bodybuilding forums describe 14-day, 21-day and repeated on/off patterns, but these are not approved treatment schedules for cutting or weight loss.
Why do so many discussions mention 14 days?
The two-week format appears in older guides and was repeated across several large forums. Its popularity online should not be mistaken for clinical evidence that two weeks is effective or safe.
What is the difference between a first and second cycle?
Some guides publish a separate repeat-cycle schedule with higher quantities. They are claims made by the authors, not medically established adjustments for people who have used the drug before.
Is a 21-day cycle better than a 14-day cycle?
No reliable clinical evidence establishes that extending a nonmedical cycle to 21 days provides better results or makes the exposure safer. Longer exposure may simply extend the time during which harmful effects can occur.
Does two weeks off make another cycle safe?
No. An off-period is a calendar feature of some forum schedules, not proof of cardiovascular recovery or a medically validated reset of risk.
Can supplements prevent cramps or other side effects?
Forum posts often mention taurine, potassium and hydration. These claims do not demonstrate that supplements prevent arrhythmia, heart injury or other serious toxic effects. Potassium supplements themselves can cause problems when taken inappropriately.
Do the same cycles apply to men and women?
No safe fat-loss regimen has been established for either group. Sex-specific dosage claims on forums are not a substitute for human safety and effectiveness studies.
Is clenbuterol an anabolic steroid?
No. It is a beta-2 adrenergic agonist. Human and animal research has examined its effects on body composition. Its beta2-receptor mechanism differs from that of anabolic-androgenic steroids.
Original forum discussions and references
Publication dates identify the opening threads; later replies and edits may differ from the first post. The references distinguish original proposals, personal accounts, copied guides and medical observations.
Original plans and personal accounts
- EliteFitness - Clenbuterol FAQFebruary 2003. BigAndy69 first- and repeat-cycle examples.
- AnabolicMinds - Clenbuterol Cycle - Need CriticismMay 2014. Proposed 14-day first cycle and replies.
- EliteFitness - The Best Way to Use ClenbuterolMarch 2013. Proposed three-part daily schedule.
- Bodybuilding.nl - ClenbuterolMarch 2013. Four stages followed by a planned break.
- Bodybuilding.nl - Hoe en wat Clenbuterol?January 2016. Five-stage schedule posted in a reply.
- AnabolicMinds - Clenbuterol CycleApril 2012. A proposed 21-day schedule.
- AnabolicMinds - Clenbuterol InfoJuly 2014. Another proposed 21-day schedule.
- AnabolicMinds - Clenbuterol & T3 StackMarch 2011. Proposed three-week stages involving different substances.
- EliteFitness - Off Time Between Clen CyclesOctober 2016. Repeated two-week periods of use and breaks.
- Forumoretesto - Personal Experience with Sports PharmacologyJanuary 2018. Six-week cutting account involving multiple drugs.
Guides, related discussion and reposts
- SportWiki - Clenbuterol for Cutting and Weight LossTwo-week guide and other combinations.
- EliteFitness - ClenbuterolAugust 2014. Article describing alternative on/off patterns.
- AnabolicMinds - Clenbuterol HandbookA repost of the BigAndy69 guide, not a separate firsthand cycle.
- MuscleChemistry - Clenbuterol FAQContains the same first- and repeat-cycle figures as the earlier FAQ.
- SteelFactor - Clenbuterol, page 8Russian-language forum discussion and copied guidance.
- SteelFactor - Clenbuterol, main topicLong-running discussion with user experiences.
- GymOnline - ClenbuterolOlder Russian-language article with alternative views on cycling.
Medical and anti-doping references
- Poison Control - Clenbuterol: Unapproved and UnsafeMedical overview of toxicity and emergency advice.
- Brett, Dawson and Brown, Medical Journal of Australia, 2014Retrospective analysis of 63 reported exposures.
- Spiller et al., 2013, PubMedClinical adverse events in misuse for bodybuilding and weight loss.
- USADA - Athlete Guide to Anti-DopingClenbuterol appears under other anabolic agents on the prohibited list.