There's little evidence to support the effectiveness of most substances thought of as natural aphrodisiacs.
Although certain foods and supplements — such as chocolate, spicy food and saw palmetto — are sometimes claimed to affect libido, research has shown them to be largely ineffective at producing a sexual response in either men or women.
While there's no harm in experimenting with most foods to see if they're effective natural aphrodisiacs, be aware that some supplements containing insect or plant extracts can be toxic. For example, Spanish fly, a commonly touted natural aphrodisiac, can cause kidney damage and gastrointestinal bleeding.
Certain products marketed as natural aphrodisiacs have also been found to contain prescription drug ingredients — such as sildenafil, the active ingredient in the erectile dysfunction drug Viagra — that aren't disclosed on the label. These ingredients can be dangerous if you have certain medical conditions or you're taking particular medications.
If you're looking for an effective way to increase your sexual desire, consult your doctor. He or she may suggest proven strategies for enhancing sexual health, such as communicating with your partner, making healthy lifestyle choices and treating any underlying medical conditions. It may also help to consult a counselor or therapist who specializes in sexual concerns and relationship issues.