Using citrulline supplement may be necessary if you suffer from certain health conditions, but it is very important to understand the physical effects and the potential risks before use.
What is Citrulline?
Citrulline is an amino acid that plays a key role in circulatory health and energy metabolism and is one of the three amino acids involved in the urea cycle. Discovered more than a century ago, l-citrulline is considered a non-essential amino acid and is converted by the body into l-arginine (another amino acid) and nitric oxide. Both of these compounds play critical roles in the body, particularly in relation to blood pressure, immune system issues, and heart diseases. 
Some people prefer to take citrulline supplements, rather than arginine supplements, because the former will maintain arginine plasma levels for a longer time, rather than delivering a single spike in those levels. If you’re looking for citrulline in your health food or supplement store, it may be under the name citrulline malate, the chemical form of the supplement, rather than the pure amino acid.
The top benefits of this amino acid include the following:
- Improving blood flow
- Preventing heart diseases
- Reducing muscle soreness
- Treating erectile dysfunction
- Boosting immunity
Let us discuss them in detail below.
Fatigue and Muscle Soreness
Studies have found that regularly using this amino acid supplement before a workout can not only reduce muscle fatigue and soreness but also improve the energy production of the body and boost the efficiency of your exercise. 
When people struggle with high blood pressure, erectile dysfunction and fertility problems are often a secondary side effect. When using these amino acid supplements, blood pressure can drop and circulation will improve, thus clearing up your ED symptoms. Be careful about taking this supplement at the same time as other ED medication. 
As mentioned, this amino acid is closely related to the circulatory system, and by improving the flow of blood throughout the body, it is able to help deliver more oxygen and essential resources to the cells and muscles.
By optimizing the body’s anaerobic and aerobic processes, this amino acid can help control your blood pressure, relieving many of the symptoms of hypertension. This can further lower your risk of atherosclerosis, heart attack, and stroke. 
In order for your body to produce its required amount of HGH (Human Growth Hormone), a great deal of arginine is required. Citrulline is converted into arginine after it’s consumed, meaning a higher level of HGH and better results for bodybuilders. 
When training hard, your immune system can be more easily compromised, but studies have found that supplementation with l-citrulline can give the immune system support and protection. 
Sickle Cell Anemia
One of the major symptoms of sickle cell anemia is a very low level of nitric oxide in the bloodstream. When citrulline is converted to arginine, it also releases nitric oxide, helping to treat this disease. 
Citrulline Food Sources
While some people choose to take l-citrulline supplements, you can also naturally boost your levels of this non-essential amino acid through your diet, including foods like the following:
If you are recommended a supplement, the typical dosage should not exceed 5 grams in one day. If you are taking citrulline malate, do not consume more than 6-8 grams per day. In terms of specific instructions on when to take the supplement for maximum workout efficiency, consume your dosage 20-30 minutes before your workout begins. 
Citrulline Side Effects
There can be a few side effects to citrulline, these include the following:
- Stomach upset: There are no known allergic reactions to citrulline supplementation, although some people report stomach upset when an excessive amount is taken.
- Drug interactions: When taken in conjunction with other drugs, there could be negative interactions, particularly in the case of nitrates, erectile dysfunction drugs, or medications for blood pressure. 
- Pregnancy & Breastfeeding: Due to the strong impact on the body, pregnant and breastfeeding women should avoid taking these supplements, and should rely solely on food sources.