What is carnitine (L-carnitine)?
Carnitine is an amino acid synthesized by the body from the foods we eat (red meat and dairy products). This process produces energy and is used primarily for muscle function, so carnitine deficiency (usually rare) leads to muscle weakness, increased fatigue or cardiac arrhythmia. However, several researchers have been interested in carnitine as part of infertility treatments.
Carnitine and infertility: studies
Carnitine is an antioxidant: it neutralizes free radicals (source of oxidative stress) and acts as a source of energy. According to a press review published in 2017, carnitine would notably fight against oligozoospermia (decrease in the number of spermatozoa) and asthenozoospermia (decrease in the mobility of spermatozoa). Indeed, it is involved in the metabolism of spermatozoa and influences their motility. Several in vitro studies have found that carnitine-containing sperm cultures contain sperm with higher motility.
In addition, a study conducted in Pakistan has shown that low levels of carnitine can be observed in men with infertility (oligoasthenoteratozoospermia or OAT: an abnormality associating a low number of spermatozoa, a low mobility of these and a high rate of high malformed spermatozoa).
A double-blind, placebo-controlled study also highlighted improvements in sperm parameters, particularly sperm motility, in men with OAT after 2 months of carnitine treatment.
Another study, published in January 2018 and carried out on 214 patients who have already failed to carry out an in vitro fertilization, has shown (after the birth of several healthy babies) that the oral administration of carnitine would make it possible to increase the chances of pregnancy in IVF by increasing the quality of oocytes and promoting embryonic development.
In addition to improving male fertility, it appears that carnitine also has beneficial effects on women with fertility disorders. Indeed, in vivo and in vitro studies have shown that carnitine can reduce cellular stress, maintain a proper hormonal balance, stimulate energy production and maintain the robustness of oocytes.
The addition of carnitine, already present naturally in our body, would not only improve physical performance but especially improve different parameters of male and female fertility.
- Systematic review of antioxidant types and doses in male infertility: Benefits on semen parameters, advanced sperm function, assisted reproduction and live-birth rate
- Role of L-carnitine in male fertility
- Oral administration of l-carnitine improves the clinical outcome of fertility in patients with IVF treatment
- Role of L-carnitine in female infertility
- Carnitine (L-carnitine)