One process, every category
Weight loss
A medical consultation on your weight goal. Treatment if appropriate.
Sexual health
An absolutely discreet consultation for intimate concerns.
Hair growth
Medical assessment and tailored treatment for hair loss.
What the sexual health consultation covers
One questionnaire and one doctor review sit behind every sexual-health concern in this library — from erectile difficulty to infection, contraception and prevention.Erectile dysfunction
Premature ejaculation
Peyronie's disease
Performance anxiety
Low libido
Chlamydia
Urinary tract infection
Emergency contraception
HIV PrEP
How the medicines work
PDE5 inhibitors (sildenafil, tadalafil) — the cGMP pathway
PDE5 inhibitors (sildenafil, tadalafil) — the cGMP pathway
These medicines inhibit phosphodiesterase type 5 (PDE5), the enzyme that degrades cyclic guanosine monophosphate (cGMP) in the corpus cavernosum smooth muscle (StatPearls, NBK549843, 2023). During sexual stimulation, nitric oxide (NO) is released from non-adrenergic, non-cholinergic nerves and endothelial cells. NO activates soluble guanylate cyclase, raising intracellular cGMP, which lowers intracellular calcium and relaxes the trabecular smooth muscle, allowing blood to fill the sinusoids (PMID 15224127). PDE5 inhibitors prolong this signal by preventing cGMP breakdown. They have no erectogenic effect in the absence of sexual stimulation because cGMP is not raised. Sildenafil and vardenafil have a half-life of approximately 4 hours; tadalafil has a half-life of 17.5 hours, allowing responsiveness for up to 36 hours.
Why nitrates are contraindicated — explained by mechanism
Why nitrates are contraindicated — explained by mechanism
Both PDE5 inhibitors and organic nitrates (such as glyceryl trinitrate and isosorbide mononitrate) act on the same NO-cGMP pathway. Nitrates donate NO, increasing cGMP production; PDE5 inhibitors block cGMP breakdown. Co-administration produces a synergistic rise in cGMP, leading to pronounced systemic vasodilation and potentially severe hypotension. Studies in patients with stable angina found mean maximum decreases in standing blood pressure of 52/29 mmHg when sildenafil was added to isosorbide mononitrate (PMID 10903810). For this reason, PDE5 inhibitors are absolutely contraindicated in anyone using nitric oxide donors in any form.
Population considerations
Population considerations
Sildenafil and tadalafil are metabolised primarily by CYP3A4. In patients with severe hepatic impairment (Child-Pugh class C) or severe renal impairment (creatinine clearance below a clinically significant threshold), plasma levels are significantly elevated, and the reviewing doctor takes this into account when deciding on dose or suitability. In patients aged over 65, reduced clearance may also prolong exposure. Dapoxetine, a short-acting selective serotonin reuptake inhibitor used for premature ejaculation, is contraindicated in moderate-to-severe hepatic impairment and is not recommended in patients taking monoamine oxidase inhibitors or with a history of serotonin syndrome.
How it works
The questionnaire, doctor review and prescription-if-appropriate process is the same regardless of which treatment area you start from. See how the consultation works and the full set of treatment areas.Safety and confidentiality
Eligibility checks run at submission, and a registered doctor makes the clinical decision afterwards. See how we handle safety and eligibility and pricing for sexual health consultations.Start a consultation
Sexual health consultation
Answer the sexual health questionnaire and a registered doctor reviews it.
They decide whether treatment is appropriate, which one, and at what dose —
and declining is a normal outcome. See what it costs
and how the review works.