L-carnitine and Acetyl-L-carnitine
Summary of Semen Parameter Effects Reported in
Human Clinical Trials 

Updated October 2002

Author

N

Length of Tx

Treatment

Sperm Count/Conc.

Results

Sperm Motility

Results

Other findings & Comments

Campaniello, 1989

·   idiopathic asthenospermia (% motile < 30%)

·   duration of infertility (not stated);

9

3 mo.

LC - 2 g p.o. b.i.d.

Sperm count was not affected (no data presented)

·   Mean % motility incr. 88% at 3 mo. from 25 to 47% (p < .01)

·   one pregnancy reported

Costa, 1994

·   multicenter trial (4);

·   idiopathic asthenospermia
- % motility > 20 but < 40%;
- sperm conc. > 10 x 106 /ml;
- RLP < 20%
- linearity index (CASA) 2 to 4;

·   sampling done at  T-2 mo., T0 (start of trial), T+2 mo., T+4 mo , T+6 mo.;

·   analysis includes pts. grouped by degree of motility impairment.

100

4 mo.

LC – 1 g p.o. t.i.d..

·   Mean sperm concentration incr.
7.7% from 49.4 to 53.2 x 106/ml at T+4 (p<.001)

·   Mean total sperm count incr.
10.6% at T+2 (from142 to 157) and 14.7% at T+4 (to 163.3 x 106 ) (p<.001)

·   Mean % motile incr.
17.8% at T+2 (from 26.9 to 31.7); 
35.3% at  T+4 (to 36.4%) and
40.1% at T+6 (to 37.7%) (all p<.001).

·   Mean % RLP incr.
28.7% at T+2 (from 10.8 to 13.9%)
61.1% at T+4 (to 17.4%) and
66.7% at T+6 (18%). (all p<.001)

·   Mean velocity (CASA) incr. (p<.001) at T+2 and mean velocity, linearity index & max. amplitude  sign. incr. (p < .001) at T+4.

·   Among pts. with % RLP < 5 (T0):

Mean % motile incr. 77.2% at T+2 (from 19.3 to 34.2), 111% at T+4 (to 40.9%) and 68.9% at T+6 (decline from T+4 to 32.6%). (all p<.001)

Mean % RLP incr. 412% at T+2 (from 3.1 to 15.9%), 554% at T+4 (20.3%) and at T+6 (20.0%).(p<.001)

Less but  till sign. incr. in group with % RLP 5-10% but not in groups with 11-15% or 16-20% RLP.

·   mean % abn. morphology sign. decr. (p<.001) at T+6 (45.9 to 42.9%).

Lombardo, Gandini et al. 2002

·          Age 20-40 yr

·          Infertility duration >2 yr

86

2 mo.

LC – 2 g p.o. daily

Compared to placebo significant improvement in sperm concentration in LC treated (p = 0.01).

·   Treatment increased percentage motility (P = 0.04) and forward sperm progression (P = 0.05). 

·   The increase in forward sperm progression was more significant in patients with severe oligo-asthenospermia, <5 X 106 forward motile sperm /ejaculate or <2 X 106 forward motile sperm/mL (P = 0.03, and 0.02, respectively).

·   L-carnitine supplementation significantly improves the two of the most important sperm parameters: concentration and motility and further it improves these parameters in patients with severe oligo-asthenospermia

Loumbakis, 1995

·         idiopathic asthenospermia

20

6 mo.

LC – 1 g p.o. daily

Sperm count was not affected. (no data presented)

·   Mean % motility incr. at 6 mo. from 24.7 to 42.8% (p < .01)

·   LC seminal fluid conc. -  200 nMol/ml in asthenospermic group compared to 700 nMol/ml in fertile group

Micic, 1998

·   idiopathic oligoasthenospermia
- sperm. conc. < 20 x 106/ml;
- % prog. motility < 20%;;

·   control group (N=20);

·   duration from 16 to 24 mo.;

60

3 mo.

LC - 3 g p.o. daily

·   Group A (severe oligospermia, initial concentration < 5 x 106/ml) – mean sperm concentration increased 209% from 1.26 to 3.9 x 106/ml (p=.014).

·   Group B (oligospermia, initial concentration > 5 x 106/ml) – mean sperm concentration increased 67% from 13.7 to 22.9 x 106/ml (p=0.007)

·   Group A  – mean % progressive motility incr. from 5 to 14% (p=0.004)

·   Group B – mean % progressive motility incr. from 14 to 22% (p=0.006

·   Seminal LC: 
- Group A – incr. from 667 to 948 µmol (p<0.001).
- Group B – incr. from 719 to 1,192 µmol (p<0.001).

·   No difference in semen parameters among infertile control group before and after 3 mo. period.

Micic, 1995

·   History of infertility

26

3 mo.

LC – 2 g p.o.

3 times daily.

no observations reported

·   92% pt had incr. in motility measured by “swim up” procedure (p=0.01)

Moncada, 1992

·   idiopathic oligoasthenospermia;

·   infertility from 16 to 24 mo.;

·   sperm. conc. < 20 x 106/ml;

·   % prog. motility < 50%;

·   4 mo. post treatment follow-up

·   females had normal hormones, bi-phasic BBT & patent tubes

20

2 mo.

ALC – 2 g p.o. twice daily.

·   Mean sperm concentration increased 44.9% from 9.8 to 14.2 x 106/ml.  t-Test NS but F-Test sign. at p<.01. 

Note:  11/20 had mean 55% incr. in conc. (50-233%).  3/5 with initial conc. <5 x 106/ml and 6/11 with conc. of 6-10 x 106/ml had positive response ranging from 37 to 233%

·   Mean % motility incr. at 2 mo. from 21.7 to 38.2% (p < .003) in 15 pt., >40% in 12,

·   no diff. in morphology

·   at 4 mo. after d/c ALC, no stat. sign. diff. in semen parameters noted.

·   7 pregnancy - 5 wives at end of 2nd mo. and 2 others, one each at end of 3rd and 4th mo.

Muller-Tyl, 1988

·          idiopathic asthenospermia;

·          Group A (motility detected at 24 hr post sample collection);

·          Group B (no late motility detected);

·          Group C (no late motility and LC treated);

·          Control (N=14 fertile men)

30

4 mo.

LC – 1g intravenously, once daily

·   Mean sperm concentration increased 46% from 45 to 65 x 106/ml at 8 weeks

·   Group C – 3 of 7 pts with late motility after 8 wks. of treatment.

·         Lower seminal plasma conc. of total, free and acyl-carnitine in Group B & C

·         Lower sperm conc. of total, free and acyl-carnitine in Group B and C that improved in Group C with treatment.

Vicari, 1997

·   s/p antibiotic tmt of Chlamydia or bacterial epididymitis and ROS overproduction

(16 asthenospermic with 2 failed IVF programs and 16 with oligoasthenospermic and Hx of infertility)

10

14 da.

Group A: ALC 1.5g t.i.d. x 14 da.,

·   Grp A:  post Tx median ROS values significantly lower than pre-treatment levels and post-treatment levels of Grp-B & C.  ROS production normalized in 60% of cases

10

14 da.

Group B: Vit E, 300mg t.i.d. x 14 da.

·   Grp B:  no significant difference in median ROS values.  ROS reduced in 30% of cases

12

14 da.

Group C: no Tx controls

·   Grp C: no significant difference in median ROS values.  No individual reduction in ROS production observed.

Post Tx IVF Results                 oocytes obtained    % fertilized              # pregnancies

                Grp A                                      59                 66.1%                         2

                Grp B                                       61                 24.5%                          0

                Grp C                                       58                   8.6%                          0