Escitalopram is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. Escitalopram is the (S)-stereoisomer (enantiomer) of the earlier Lundbeck drug citalopram, hence the name escitalopram. The similarity between escitalopram and citalopram has led to accusations of "evergreening", an accusation that Lundbeck has rejected. Independent analysis has found all SSRIs to be more or less equivalent in benefits. When both published and unpublished trials are taken into account the benefit appears to be little to none in those with mild or moderate depression. Escitalopram, like other SSRIs, has been shown to affect sexual functions causing side effects such as decreased libido, delayed ejaculation, genital anesthesia, and anorgasmia. Although usually reversible upon discontinuation, these sexual side effects can last for months or years or be permanent after the drug has been completely withdrawn.