How fast does sublingual sildenafil work, and how long does it last? The orodispersible forms approved in Europe give the same blood levels as the ordinary tablet and carry the same timing: usually half an hour to an hour to start, and sildenafil's usual window of up to 4 hours. Small studies suggest sildenafil taken under the tongue can reach the blood sooner, but none has changed a label. In Australia, sublingual wafers are registered, on prescription; the European forms and Kamagra Oral Jelly are not.
What forms of sildenafil dissolve in the mouth?
Three are approved somewhere. In Australia, sildenafil 25 mg and 50 mg sublingual wafers, sold as Wafesil, are made to be placed under the tongue (ARTG 288497). In Europe, Viagra also comes as a 50 mg orodispersible tablet, which dissolves on the tongue in seconds and is then swallowed, and as a 50 mg orodispersible film, left on the tongue to dissolve (EMA product information). Strictly, those two go on the tongue, not under it. Oral jellies and chewable tablets are sold online too, but none is on the Australian register; the chewables are covered in BlueChew chewable sildenafil, and an ordinary tablet held under the tongue in can Viagra be dissolved and absorbed under the tongue?
How fast do they work?
On the label, as fast as the tablet. Taken without water, the orodispersible tablet gave the same blood levels as the 50 mg film-coated tablet, and so did the film (EMA product information). The leaflet's timing is the tablet's too: it "normally takes between half an hour and one hour", taken about one hour before sex (EMA package leaflet). Food matters more for these forms: after a high-fat meal the orodispersible tablet reached its peak about 3.4 hours later, at a level 59% lower, so it is taken on an empty stomach (EMA product information). The register entry for the wafers gives no timing. The tablet's own timing is in how long does sildenafil take to work?
Is it faster when held under the tongue?
Possibly, going by one small study. In 20 men with erectile dysfunction, a 50 mg orodispersible film held under the tongue gave a blood level of 13.5 ng/mL after 15 minutes, against 2.24 ng/mL for the same dose swallowed as a tablet, and about three times the tablet's exposure over the first hour (De Toni et al., 2018). It measured blood levels, not erections. A second study, of 12 healthy men, found the film gave similar blood levels under the tongue or on it (Loprete et al., 2018), and on the tongue it matches the tablet (EMA). The evidence does not settle it, and no label claims a faster start.
Where do the "15 minutes" and "40 minutes" figures come from?
From one small study. In a Turkish trial published in 2004, 20 men with erectile dysfunction were given 20 mg of sublingual sildenafil and 20 a placebo. Thirteen of the 20 on sildenafil had satisfying erections and intercourse, against 3 on placebo; the effect began on average after 15.5 minutes and "lasted for an average of 40 min" (Deveci et al., 2004). The abstract does not say how the dose was prepared or what the 40 minutes measured, and no group took a swallowed tablet, so neither figure can be set against the tablet's timing.
How long do they last?
No label gives these forms a different duration from the tablet, whose blood levels they match. For sildenafil, "The effects of the medicine can last for up to 4 hours. This means that the ability to have an erection can occur during this 4 hour period, but the actual erection will only last for a normal period of time" (healthdirect). More in how long does sildenafil last?
Are they registered in Australia?
The wafers are; the others are not. A search of the register for sildenafil lists tablets, capsules, sublingual wafers, an oral suspension and an injection (ARTG). The 25 mg and 50 mg wafers have been registered since 14 June 2018, as Wafesil and under three other names from the same sponsor; Wafesil is registered for erectile dysfunction in adult men and is prescription-only (healthdirect — Wafesil). No orodispersible tablet or film is on the register, and Kamagra Oral Jelly is not on it either. Products not listed in the ARTG "are not approved for supply in Australia, have not been reviewed for safety or quality" (TGA).
Are the side effects any different?
No: it is the same medicine, with the same common side effects, such as headache, flushing, a blocked nose and indigestion (healthdirect), and never with nitrates. One dose a day is the limit, and the European leaflet says not to combine the orodispersible tablets with any other sildenafil product (EMA package leaflet).
The short answer
The orodispersible tablets and films approved in Europe are labelled to work like the tablet: in about half an hour to an hour, with a window of up to 4 hours, on an empty stomach. In Australia only the sublingual wafers are registered, on prescription. Which ED medicine starts soonest is compared in the fastest-acting ED medications, and how well sildenafil works in our guide to Viagra effectiveness.
