Clenbuterol Side Effects

Clenbuterol is a stimulant and bronchodilator used in some countries around the world to treat asthma and other similar conditions. In the performance enhancement world, Clenbuterol (or Clen) is a weight loss supplement designed to help burn visceral and subcutaneous fat. Clenbuterol side effects can range from mild to severe, but following the Clenbuterol dosage and cycling guidelines can help you mitigate the risks.

What Does Clenbuterol Do in Your Body?

To better understand Clenbuterol side effects, it is helpful to first understand how and why this drug works to burn fat. Clenbuterol acts on the sympathetic nervous system to suppress the appetite and make one feel more energetic. It also creates a thermogenic effect, which simply means it boosts the core body temperature slightly, thereby increasing the metabolism and allowing for more efficient calorie burning. Finally, this drug triggers the existing fat cells in the body to release their stores.

This combination of effects can make a profound difference in an athlete or bodybuilder’s physique, but only when he or she combines Clen with a rigorous diet and exercise plan. Rather than viewing Clen as a miracle drug that can simply melt away fat, it is best to view it as an “amplifier”, or product that enhances the results you would see with diet and exercise alone.

Stimulant Clenbuterol Side Effects

The clear majority of Clenbuterol side effects are the result of the drug’s stimulant effect. These side effects very closely resemble those of high doses of caffeine, and they include:

  • Hypertension (high blood pressure);
  • Increased resting heart rate (RHR);
  • Insomnia and other sleep disturbances;
  • Heart palpitations;
  • Tremors (especially in hands);
  • Feelings of anxiety, nervousness, and/or restlessness;
  • Sweating;
  • Shallow breathing;
  • Headaches; and
  • Dry mouth.

People will experience the stimulant Clenbuterol side effects to varying degrees. In most cases, the severity of the side effects eases with time and they will completely disappear on their own during a Clen cycle.

Other Clen Side Effects

Not all the side effects of Clenbuterol are due to its stimulant nature, and due to a lack of studies and human trials, the long-term effects are not completely known. In animal trials, long-term Clenbuterol side effects are as follows:

  • Enlarged heart muscle (due to increase in collagen production);
  • Worsening heart conditions;
  • Increasing bone fragility/loss of bone density; and
  • Left-sided cardiac atrophy.

Due to the potential severity of these side effects, individuals should follow Clen dosing guidelines carefully and stick to recommended cycles.

Who Should Not Take Clenbuterol?

Clenbuterol side effects can exacerbate certain medical conditions, so if you have any of the conditions listed below, you should not use this supplement:

  • Heart conditions – Clen can create a host of cardiac issues, especially in patients with preexisting conditions. If you have (or have had) heart problems, you should not use Clen.
  • High blood pressure – If you have high blood pressure, this supplement can drastically increase your risk of heart attack or stroke.
  • Diabetes – Clen can have an adverse reaction on your insulin sensitivity and production, so you should not use it if you have diabetes or are at risk.
  • Liver or kidney problems – Long term use of Clenbuterol can lead to liver or kidney damage, so you should not use if it if you have renal conditions.
  • Gastrointestinal diseases – Clenbuterol has been shown to cause stomach ulcers.
  • Conditions requiring blood thinners – Clenbuterol should not be taken alongside blood thinners, including drugs like Warfarin or even aspirin.
  • Pregnancy or breastfeeding – Clenbuterol can harm an unborn fetus, and it can also pass into breastmilk. Women who are pregnant, may become pregnant, or breastfeeding should not use Clen.

Mitigating and Avoiding Clenbuterol Side Effects

Now that you understand the potential severity of Clenbuterol side effects, you may wonder what you can do to mitigate them. By far, the best way to avoid adverse reactions to Clen is to follow dosing guidelines. Men and women alike can benefit from this fat-burning supplement, but because women react more favorably to Clen in lower doses, they will need to take much less.

Along those same lines, Clenbuterol doses should always be titrated. The human body develops a tolerance to Clenbuterol very quickly, so the stimulant effects can be mitigated by slowly titrating the dose upward over a period of about two weeks. For this reason, most people who have used Clen successfully will recommend a two-week-on/two-week-off cycle. The chart below shows a sample Clenbuterol cycle for both men and women.

TimeframeDaily Dose (Men)Daily Dose (Women)
Days 1-3
40mcg
20mcg
Days 4-6
80mcg
40mcg
Days 7-9
100mcg
60mcg
Days 10-12
120mcg
80mcg
Days 13-14
140mcg
100mcg

Keep in mind that not everyone will be able to tolerate the maximum Clenbuterol dose, which is 140mcg per day for men or 100mcg per day for women. Titration helps in this regard by allowing you to discover your own personal limits. Should you experience bothersome side effects at any point during this two-week cycle, simply back down to the last comfortable dose and use that until the end of the cycle. Following the two weeks, take a two-week break, then resume your cycle as normal. You can do this indefinitely as long as you do not take Clen for more than 16 weeks out of each year.

Alternative Clen Cycles

Clenbuterol Side EffectsTwo-week cycling is not the only way to avoid significant Clenbuterol side effects, fortunately. Many people enjoy a great deal of success using Clen for longer periods of time, but at much lower doses. This is especially helpful for those who want the thermogenic fat-burning effects, but who are not fond of the stimulant Clenbuterol side effects that can make them feel jittery. In this case, you would simply use Clen at lower doses over the course of six to 10 weeks, adjusting the cycle length based on dose.

For example, if you are a man taking the maximum dose of 140mcg per day, you should keep your cycle at just six weeks. If you are a woman using only 60mcg per day, this is roughly half of the max dose, so you can use it for as long as 10 weeks. Another alternative involves using low-dose Clen for the full 16 weeks out of the year. In this case, you would not use more than half the maximum dose, but you would take it every day for 16 weeks or until you reach your weight loss goals.

Clenbuterol side effects range from mild to severe, and their severity is influenced by a number of factors like dose and cycle. For the best results, use the lowest dose of Clenbuterol that provides results for the shortest time possible. This will help you reach your goals without putting yourself at increased risk.