Sildenafil Oral Jelly 100mg typically starts to work within 15 to 30 minutes after ingestion. However, it can take up to an hour for its full effects to be realized. Most users report that they begin to feel the effects within 15 to 30 minutes. The maximum effectiveness usually occurs around 1 hour after taking the medication. Taking it on an empty stomach may enhance its effectiveness, as fatty meals can delay its onset. Like all medications, it may have side effects, so discussing potential risks with your doctor is important.