Plain English Summary
Background and study aims
Infertility is when a couple cannot get pregnant (conceive), despite having regular unprotected sex. 10-15% of reproductive-aged couples trying to achieve pregnancy remain childless. Nearly half of all cases of infertility are due to male infertility. Male infertility is caused by abnormal sperm. In 45% of subfertile or infertile men the cause is unknown. This condition is called idiopathic (oligo)±(atheno)±(terato)spermia (iOAT). There are reports showing that the supplement l-carnitine alone or in combination with other micronutrients improves sperm parameters (i.e., number, movement, shape of sperm). Micronutrients, often referred to as vitamins and minerals, are parts of the diet which are required by the body in small amounts. The aim of this study is to compare the short-term effects of a combination of eight micronutrients including l-carnitine versus l-carnitine alone on sperm parameters as a treatment for iOAT.
Who could participate?
Infertile men aged 20-60
What did the study involve?
Participants are allocated to one of two groups. Participants in group 1 are given l-carnitine twice a day for three months. Participants in group 2 are given a combination of eight micronutrients including l-carnitine once a day for three months. Each participant provides two sperm samples before and then again after the treatment period. The samples are then analysed for sperm count and mobility (how well they move).
What were the possible benefits and risks of participating?
Participants may benefit from improved sperm quality. No side effects are expected.
Where was the study run from?
Karl Landsteiner Institut für zellorientierte Therapie in der Gynäkologie (Austria)
When did the study start and how long did it run?
January 2004 to January 2014
Who was funding the study?
Investigator initiated and funded
Who is the main contact?
1. Prof. Dr Martin Imhof
2. Dr Markus Lipovac
Dr Markus Lipovac
Wiener Ring 3-5
Prof Martin Imhof
Wiener Ring 3-5
Sperm parameter protocol 1.03/2014
Comparison of the effect of a combination of eight micronutrients versus a standard mono preparation on sperm parameters
To compare the short term effects of a combination of eight micronutrients including l-carnitine vs. a mono-substance (l-carnitine alone) on sperm parameters showing superoirity of the combination over the mono-substance concerning different semen parameters.
Local ethics board of the General Teaching Hospital Korneuburg, Austria, 14/12/2004, No.5/2004
Double-centre prospective open-labelled non-randomized study
Primary study design
Secondary study design
Non randomised study
Patient information sheet
Not available in web format, please use contact details below to request a patient information sheet.
Reduced reproductive capability in men presenting an unexplained (unidentified) abnormal semen analysis
A total of 299 participants who met the inclusion criteria were invited to participate. Participant number 1 was allocated to group 1, participant number 2 to group 2, participant number 3 to group 1 etc, to receive treatment for three months with:
1. A mono-substance (500 mg l-carnitine/twice a day, n=156)
2. A combined compound (440 mg l-carnitine + 250 mg l-arginine + 40 mg zinc + 120 mg vitamin E + 80 mg glutathione + 60 µg selenium + 15 mg coenzyme Q10 + 800 µg folic acid/once a day, n=143; Profertil®, Lenus Pharma GmbH, Vienna, Austria)
Semen analysis was performed at baseline and after three months of treatment.
Primary outcome measures
The following sperm parameters were analysed at baseline and after 3 months of treatment:
1. Sperm volume (ml)
2. Sperm density (mio/ml)
3. Overall, fast and slow progressive motility (expressed as %)
4. % of sperm with normal morphology
All parameters were defined according to WHO guidelines (4th edition). Sperm analysis was performed with an automatic, computer analysing system called Sperm Class Analyzer® CASA System, by MICROPTIC SL, company based in Barcelona, Spain.
Secondary outcome measures
Overall trial start date
Overall trial end date
Participant inclusion criteria
2. 20 to 60 years of age
3. Suffering from at least one year of subfertility
4. At least one recent pathological semen analysis result
Target number of participants
Participant exclusion criteria
4. Recent urogenital infections
5. Hormonal disorders.
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Trial participating centre
Med 19 Study Center of Vienna
Karl Landsteiner Institute of Cell-Based Treatment in Gynecology (Karl Landsteiner Institut für zellorientierte Therapie in der Gynäkologie)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
To be confirmed at a later date
Intention to publish date
Participant level data
Not expected to be available
Results - basic reporting
2016 results in: http://rbej.biomedcentral.com/articles/10.1186/s12958-016-0219-0