Cialis

Cialis (Tadalifil citrate), a phosphodiesterase type 5 inhibitor, is used to treat erectile dysfunction (ED) and decreased libido in males. Cialis works by aiding relaxation of blood vessels and increasing blood flow in the penis during sexual arousal, resulting in improved erectile function. Cialis is much longer lasting than Viagra. Effects can be felt anywhere between 36-48 hours.

Tadalafil works by inhibiting PDE5, an enzyme found primarily in the arterial wall smooth muscle tissue of the penis and the lungs. A 20 mg dose of tadalafil is comparable to a 100 mg dose of sildenafil (Viagra). By inhibiting PDE5, tadalafil relaxes blood vessels in the penis, thereby increasing blood flow and aiding in erection.

Part of the physiological process of erection involves the parasympathetic nervous system causing the release of nitric oxide (NO) in the corpus cavernosum of the penis. NO binds to the receptors of the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation (vasodilation) in the corpus cavernosum, resulting in increased inflow of blood and an erection.

Tadalafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum. The molecular structure of tadalafil is similar to that of cGMP and acts as a competitive binding agent of PDE5 in the corpus cavernosum, resulting in more cGMP and better erections. Without sexual stimulation, and therefore lack of activation of the NO/cGMP system, tadalafil should not cause an erection. Other drugs that operate by the same mechanism include sildenafil (Viagra) and vardenafil (Levitra).

Tadalafil improves erectile function significantly, possibly increase testosterone through increased sexual activity, and is very safe.

There are limited side effects associated with its use. The most common side effects are headache, upset stomach, back pain, and muscle aches, and usually subside with in a few hours.

Of particular interest to those considering the use of Cialis is that lack of sexual activity due to erectile dysfunction actually decreases testosterone levels through a central effect on the hypothalamic-pituitary axis . Cialis was given to men for a month, and at the end, they had considerably higher testosterone levels, because they got laid more. It is unlikely that the drug has a different direct effect on the pituitary-testis axis.

This stuff is actually very safe, and was even given 3x a week to men for an extended length of time, was well tolerated, had very few sides, and was very effective. Thus, it could be another potential compound for inclusion in PCT. Tadalafil (20 mg) significantly improves erectile function, could increase testosterone, and is well tolerated, certainly something to think about after your next cycle.