Tadalafil Breakdown
Tadalafil, also known by its brand name Cialis, is a phosphodiesterase-5 inhibitor commonly prescribed for erectile dysfunction. Though, due to its effect on vasodilation (opening of the blood vessels), it is often used by bodybuilders in order to achieve a greater pump in the gym.
How it works
Tadalafil works by inhibiting an enzyme known as phosphodiesterase-5 (PDE5). This enzyme is responsible for breaking down a nucleotide called cyclic guanine monophosphate (cGMP). Since NO causes vasodilation through the downstream activation of cGMP, slowing the breakdown of cGMP with tadalafil causes NO to:
1) Work more efficiently in vasodilation
2) Elevate in concentration as a response to cGMP increases
The nitric oxide (NO) system works to induce vasodilation by the following process (shown in above picture):
NO diffuses into cell-> binds to sGC -> conversion of GTP to cGMP -> extrusion of Ca+ from cell, resulting in vasodilation
Benefits
Tadalafil has been shown in multiple studies to upregulate processes that lead to muscle protein synthesis. In layman's terms, tadalafil likely increases muscle gain (I go more in depth on this topic in this article). This study done on 12 human participants even claimed that sildenafil (a similar but inferior PDE5 inhibitor) increases muscle protein synthesis to a similar degree to that of 200mg of testosterone. The same study also showed that sildenafil significantly decreased muscle fatigue when performing resistance training.
Tadalafil has also been shown to decrease blood pressure [1], and it is even prescribed for pulmonary arterial hypertension (high blood pressure in the right ventricle). While extremely low blood pressure is not favorable, erring on the moderate to low side of blood pressure is associated with a decrease in cardiovascular diseases and other myocardial complications.
As it's original intended use was for erection quality, tadalafil also drastically improves sexual performance. Users report higher levels of stimulation, improved sexual arousal, and increased erection quality.
Risks
Surprisingly, tadalafil has little to no risks associated. One tadalafil meta-analysis [2] done over the course of 18-24 months concluded that there were no long term side effects experienced by the 700+ participants. As per the article, "tadalafil at doses of 5, 10, or 20mg taken as needed up to once daily for 18 to 24 months was safe and well tolerated".
Short-term, there are two very common side effects that around 10-15% of people seem to experience: headaches and dyspepsia (stuffy nose). These do not indicate any danger - they're simply a byproduct of tadalafil's mechanism. In my experience, the headaches and dyspepsia subside after a few doses. Other short-term side effects include nasopharyngitis and back pain, but these are much less common than the two formerly mentioned.
Female Use
There have been very few studies done on tadalafil's effect on females, as there is really no practical use for an erectile dysfunction medication for females (though we do know that it does have very similar effects on muscle vasodilation as it does in males). Looking at the data we do have, it still seems to be safe and well tolerated. In one study [3], a small subject group of females reported increased quality of life, improved sexual arousal, and improved orgasm quality.
Personally, I know many females that take tadalafil and they report similar effects in both muscular vasodilation and sexual function.
Dosing
Tadalafil has been reported to be safe and well-tolerated in doses ranging from 5-20mg, but I find that 5mg is efficient and causes little to no short-term side effects. Users that take more than 10mg daily often report developing a "tolerance" to tadalafil (anecdotally - there is no data I can find regarding this), but this doesn't seem to happen at 5mg daily.
I have taken 5mg daily for the last 2 years and I've seen nothing but benefits.
Where to Purchase
Tadalafil can be purchased at Researchem.store, and you can use code "Julian" at checkout to save some money.
Full disclosure - I am a Researchem affiliate, but I would not advise anyone to use research compounds without doing their own research first.
Looking to learn more about tadalafil and similar compounds? Book a call with me here
Sources
[1] Dean Patterson, Gordon T McInnes, John Webster, Malcolm M Mitchell, and Thomas M MacDonald (2006) Influence of a single dose of 20 mg tadalafil, a phosphodiesterase 5 inhibitor, on ambulatory blood pressure in subjects with hypertension
[2] F Montorsi, B Verheyden, E Meuleman, K-P Jünemann, I Moncada, L Valiquette, A Casabé, C Pacheco, J Denne, J Knight, S Segal, V S Watkins (2004) Long-term safety and tolerability of tadalafil in the treatment of erectile dysfunction
[3] Salvatore Caruso, Carla Cicero, Mattea Romano, Lucia Lo Presti, Betty Ventura, Chiara Malandrino (2012) Tadalafil 5 mg daily treatment for type 1 diabetic premenopausal women affected by sexual genital arousal disorder