Tadalafil can be synthesized starting from D – tryptophan methyl ester and piperonal via a Pictet—Spengler reaction. Tadalafil was approved in in the United States for the treatment of pulmonary arterial hypertension [28] and is under regulatory review in other regions for this condition. Some common side effects include headaches, back pain, nasal congestion, or flushing. What side effects can this medication cause? This medicine works best when you take it on an empty stomach an hour before sex. Taking generic ED medications is an effective way to save money without sacrificing quality. These are commonly prescribed for an enlarged prostate or male pattern baldness.AdComplete the Online Consultation with our Doctor. Personalize Your Needs. If Appropriate, Get a Prescription for ED from RexMD®. Free Shipping AvailableFree Shipping · Real Doctors · Discreet Packaging · Personalized Plan/5 (3, reviews)Site visitors: Over 10K in the past month. About tadalafil Brand names: Cialis, Adcirca. About tadalafil. Tadalafil is a medicine used to treat erection problems (erectile dysfunction) and symptoms of an enlarged prostate (benign prostate enlargement). It’s also sometimes used to treat pulmonary hypertension (high blood pressure in the blood vessels that supply the lungs). The recommended starting dose for Cialis intended for once daily use is mg, take at the same time each day, without regard to timing of sexual activity. This may be increased to 5mg/day based on need and tolerability. May be taken with or without food. Cialis is available as a generic, under the name tadalafil. 3.