Evidence-Based Medicine: Literature Reviews

When talking to your patients about complementary health approaches, you want to be able to answer the question: Is there any scientific evidence that this complementary product or practice works and is safe? The resources on this page will help inform you about what the science says (limited to the past 5 years).

For more information please contact the NCCIH Clearninghouse.

Açaí - Randomized Controlled Trials (PubMed®)
Açaí - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Acupuncture - Randomized Controlled Trials (PubMed®)
Acupuncture - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Acupuncture for Chronic Pain - Randomized Controlled Trials (PubMed®)
Acupuncture for Chronic Pain - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Aging - Randomized Controlled Trials (PubMed®)
Aging - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Aloe Vera - Herb-Drug Interactions (PubMed®)
Aloe Vera - Randomized Controlled Trials (PubMed®)
Aloe Vera - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Alzheimer's Disease / Dementia - Randomized Controlled Trials (PubMed®)
Alzheimer's Disease / Dementia - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Antioxidants - Randomized Controlled Trials (PubMed®)
Antioxidants - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Anxiety - Randomized Controlled Trials (PubMed®)
Anxiety - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Anxiety and Complementary Health Approaches - Randomized Controlled Trials (PubMed®)
Anxiety and Complementary Health Approaches - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Aromatherapy - Randomized Controlled Trials (PubMed®)
Aromatherapy - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Artemisinin - Randomized Controlled Trials (PubMed®)
Artemisinin - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Arthritis - Randomized Controlled Trials (PubMed®)
Arthritis - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Asthma - Randomized Controlled Trials (PubMed®)
Asthma - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Attention-Deficit Hyperactivity Disorder (ADHD) - Randomized Controlled Trials (PubMed®)
Attention-Deficit Hyperactivity Disorder (ADHD) - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Autism - Randomized Controlled Trials (PubMed®)
Autism - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Autism Spectrum Disorder and Complementary Health Approaches—Randomized Controlled Trials (PubMed®)
Autism Spectrum Disorder and Complementary Health Approaches—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Avermectin - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Ayurvedic Medicine - Randomized Controlled Trials (PubMed®)
Ayurvedic Medicine - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Benign Prostatic Hyperplasia and Complementary and Integrative Approaches—Randomized Controlled Trials (PubMed®)
Benign Prostatic Hyperplasia and Complementary and Integrative Approaches—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Benign Prostatic Hyperplasia and Complementary Health Practices - Randomized Controlled Trials (PubMed®)
Benign Prostatic Hyperplasia and Complementary Health Practices - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Black Cohosh - Randomized Controlled Trials (PubMed®)
Black Cohosh - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Black Cohosh: Herb-Drug Interactions (PubMed®)
Bodybuilding - Randomized Controlled Trials (PubMed®)
Bodybuilding - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Calcium - Randomized Controlled Trials (PubMed®)
Calcium - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Cancer - Randomized Controlled Trials (PubMed®)
Cancer - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Cannabis - Randomized Controlled Trials (PubMed®)
Cannabis - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Chamomile - Randomized Controlled Trials (PubMed®)
Chamomile - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Chelation for Coronary Heart Disease - Randomized Controlled Trials (PubMed®)
Chelation for Coronary Heart Disease - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Children’s Use of Complementary Health Approaches—Randomized Controlled Trials (PubMed®)
Chiropractic - Randomized Controlled Trials (PubMed®)
Chiropractic - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Cholesterol - Randomized Controlled Trials (PubMed®)
Cholesterol - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Chondroitin and Glucosamine - Randomized Controlled Trials (PubMed®)
Chondroitin and Glucosamine - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Coenzyme Q10 - Randomized Controlled Trials (PubMed®)
Coenzyme Q10 - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Cold and Flu - Randomized Controlled Trials (PubMed®)
Cold and Flu - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Common Cold and Complementary Health Approaches—Randomized Controlled Trials (PubMed®)
Common Cold and Complementary Health Approaches—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Complementary Health Approaches for Chronic Pain—Randomized Controlled Trials (PubMed®)
Complementary Health Approaches for Chronic Pain—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Complementary Health Approaches for Smoking Cessation—Randomized Controlled Trials (PubMed®)
Complementary Health Approaches for Smoking Cessation—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Cranberry - Randomized Controlled Trials (PubMed®)
Cranberry - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Creatine - Randomized Controlled Trials (PubMed®)
Creatine - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Cupping - Randomized Controlled Trials (PubMed®)
Cupping - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Depression - Randomized Controlled Trials (PubMed®)
Depression - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Depression and Complementary Health Approaches—Randomized Controlled Trials (PubMed®)
Dermatitis, Atopic, Acne, Impetigo, Psoriasis, Rosacea - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Detox Diets - Randomized Controlled Trials (PubMed®)
Detox Diets - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Diabetes - Randomized Controlled Trials (PubMed®)
Diabetes - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Dietary Supplements and Cognitive Function—Randomized Controlled Trials (PubMed®)
Dietary Supplements and Cognitive Function—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Dietary Supplements and Safety - Literature on Dietary Supplements and Safety (PubMed®)
Dietary Supplements for Eye Conditions—Randomized Controlled Trials (PubMed®)
Dietary Supplements for Eye Conditions—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Dimethyl Sulfoxide (DMSO) and Methylsulfonylmethane (MSM) for Osteoarthritis - Randomized Controlled Trials (PubMed®)
Dimethyl Sulfoxide (DMSO) and Methylsulfonylmethane (MSM) for Osteoarthritis - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Echinacea - Herb-Drug Interactions (PubMed®)
Echinacea - Randomized Controlled Trials (PubMed®)
Echinacea - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Erectile Dysfunction - Randomized Controlled Trials (PubMed®)
Erectile Dysfunction - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Evening Primrose Oil - Randomized Controlled Trials (PubMed®)
Evening Primrose Oil - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Eye Conditions - Randomized Controlled Trials (PubMed®)
Eye Conditions - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Eye Diseases - Randomized Controlled Trials (PubMed®)
Eye Diseases - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Fenugreek - Herb-Drug Interactions (PubMed®)
Fenugreek - Randomized Controlled Trials (PubMed®)
Fenugreek - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Fibromyalgia - Randomized Controlled Trials (PubMed®)
Fibromyalgia - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Folic Acid and Pregnancy - Randomized Controlled Trials (PubMed®)
Folic Acid and Pregnancy - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Garlic - Herb-Drug Interactions (PubMed®)
Garlic - Randomized Controlled Trials (PubMed®)
Garlic - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Ginkgo - Randomized Controlled Trials (PubMed®)
Ginkgo - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Ginkgo: Herb-Drug Interactions (PubMed®)
Ginseng - Herb-Drug Interactions (PubMed®)
Ginseng - Randomized Controlled Trials (PubMed®)
Ginseng - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Headache - Randomized Controlled Trials (PubMed®)
Headache - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Heart Disease - Randomized Controlled Trials (PubMed®)
Heart Disease - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Hepatitis C - Randomized Controlled Trials (PubMed®)
Hepatitis C - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Hepatitis C and Dietary Supplements—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Hepatitis C and Silymarin - Randomized Controlled Trials (PubMed®)
Hepatitis C and Silymarin - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Herb-Drug Interactions - Randomized Controlled Trials (PubMed®)
Herb-Drug Interactions - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Hypertension - Randomized Controlled Trials (PubMed®)
Hypertension - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Hypnosis - Randomized Controlled Trials (PubMed®)
Hypnosis - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Inflammation - Randomized Controlled Trials (PubMed®)
Inflammation - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Irritable Bowel Syndrome - Randomized Controlled Trials (PubMed®)
Irritable Bowel Syndrome - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Kratom - Randomized Controlled Trials (PubMed®)
Kratom - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Literature on Pediatric Immunization Controversy (PubMed®)
Low Back Pain - Randomized Controlled Trials (PubMed®)
Low Back Pain - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Lyme Disease - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Magnets and Pain - Randomized Controlled Trials (PubMed®)
Magnets and Pain - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Massage - Randomized Controlled Trials (PubMed®)
Massage - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Meditation - Randomized Controlled Trials (PubMed®)
Meditation - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Menopausal Symptoms and Complementary Health Practices—Randomized Controlled Trials (PubMed®)
Menopausal Symptoms and Complementary Health Practices—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Menopause - Randomized Controlled Trials (PubMed®)
Menopause - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Mental Disorders - Randomized Controlled Trials (PubMed®)
Mental Disorders - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Military Personnel - Randomized Controlled Trials (PubMed®)
Military Personnel - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Milk Thistle - Herb-Drug Interactions (PubMed®)
Milk Thistle - Randomized Controlled Trials (PubMed®)
Milk Thistle - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Mind and Body Approaches for Stress—Randomized Controlled Trials (PubMed®)
Mind and Body Approaches for Stress—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Mind and Body Practices for Fibromyalgia—Randomized Controlled Trials (PubMed®)
Mind and Body Practices for Fibromyalgia—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Mind and Body Practices for Older Adults—Randomized Controlled Trials (PubMed®)
Mind and Body Practices for Older Adults—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Multiple Sclerosis - Randomized Controlled Trials (PubMed®)
Multiple Sclerosis and Complementary Health Approaches—Randomized Controlled Trials (PubMed®)
Multiple Sclerosis and Complementary Health Approaches—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Musculoskeletal Inflammation and Natural Products—Randomized Controlled Trials (PubMed®)
Music and Health - Randomized Controlled Trials (PubMed®)
Music and Health - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Myth-Busting Popular Natural Products—Randomized Controlled Trials (PubMed®)
Myth-Busting Popular Natural Products—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Natural Products Marketed for Disease Prevention and Wellness - Randomized Controlled Trials (PubMed®)
Natural Products Marketed for Disease Prevention and Wellness - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Naturopathy - Randomized Controlled Trials (PubMed®)
Naturopathy - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
NHIS2017 - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Omega-3 and Cardiovascular Diseases - Randomized Controlled Trials (PubMed®)
Omega-3 and Cardiovascular Diseases - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Omega-3 Fatty Acids - Randomized Controlled Trials (PubMed®)
Omega-3 Fatty Acids - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Omega-3 Fatty Acids and Prostate Cancer - Randomized Controlled Trials (PubMed®)
Omega-3 Fatty Acids and Prostate Cancer - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Osteoarthritis - Randomized Controlled Trials (PubMed®)
Osteoarthritis - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Pain - Randomized Controlled Trials (PubMed®)
Pain - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Parkinson's Disease - Randomized Controlled Trials (PubMed®)
Parkinson's Disease - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Pediatrics - Randomized Controlled Trials (PubMed®)
Pediatrics - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Placebo Effect - Literature on Placebo Effect (PubMed®)
Placebo Effect - Randomized Controlled Trials (PubMed®)
Placebo Effect - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Post-Traumatic Stress Disorder - Randomized Controlled Trials (PubMed®)
Post-Traumatic Stress Disorder - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Probiotics - Randomized Controlled Trials (PubMed®)
Probiotics - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Qi Gong - Randomized Controlled Trials (PubMed®)
Qi Gong - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Qigong—Randomized Controlled Trials (PubMed®)
Qigong—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Reflexology - Randomized Controlled Trials (PubMed®)
Reflexology - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Reiki - Randomized Controlled Trials (PubMed®)
Reiki - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Reservatrol - Randomized Controlled Trials (PubMed®)
Reservatrol - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Rheumatoid Arthritis - Randomized Controlled Trials (PubMed®)
Rheumatoid Arthritis - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Safety and Complementary Therapies - Literature on Safety and Complementary Therapies (PubMed®)
Saw Palmetto - Herb-Drug Interactions (PubMed®)
Saw Palmetto - Randomized Controlled Trials (PubMed®)
Saw Palmetto - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Seasonal Affective Disorder - Randomized Controlled Trials (PubMed®)
Seasonal Affective Disorder - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Seasonal Allergies - Randomized Controlled Trials (PubMed®)
Seasonal Allergies - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Seasonal Allergies and Complementary Health Approaches—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Sexual Enhancement - Randomized Controlled Trials (PubMed®)
Sexual Enhancement - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Silymarin - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Silymarin - Randomized Controlled Trials (PubMed®)
Skin Conditions - Randomized Controlled Trials (PubMed®)
Skin Conditions - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Skin Conditions and Complementary Health Approaches—Randomized Controlled Trials (PubMed®)
Skin Conditions and Complementary Health Approaches—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Sleep Disorders - Randomized Controlled Trials (PubMed®)
Sleep Disorders - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Smoking Cessation - Randomized Controlled Trials (PubMed®)
Smoking Cessation - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Soy - Herb-Drug Interactions (PubMed®)
Soy - Randomized Controlled Trials (PubMed®)
Soy - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Spinal Manipulation - Randomized Controlled Trials (PubMed®)
Spinal Manipulation - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Spinal Manipulation and Low-Back Pain - Randomized Controlled Trials (PubMed®)
Spinal Manipulation and Low-Back Pain - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
St. John's Wort - Herb-Drug Interactions (PubMed®)
St. John's Wort - Randomized Controlled Trials (PubMed®)
St. John's Wort - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
St. John’s Wort and Depression - Randomized Controlled Trials (PubMed®)
St. John’s Wort and Depression - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
St. John’s Wort Herb-Drug Interactions - Herb-Drug Interactions (PubMed®)
Stress - Randomized Controlled Trials (PubMed®)
Stress - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Substance Use Disorders - Randomized Controlled Trials (PubMed®)
Substance Use Disorders - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Tai Chi - Randomized Controlled Trials (PubMed®)
Tai Chi - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Tea - Herb-Drug Interactions (PubMed®)
Tea - Randomized Controlled Trials (PubMed®)
Tea - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Traditional Chinese Medicine - Randomized Controlled Trials (PubMed®)
Traditional Chinese Medicine - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Type 2 Diabetes and Dietary Supplements—Randomized Controlled Trials (PubMed®)
Type 2 Diabetes and Dietary Supplements—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Urinary Tract Infections and Complementary Health Practices - Randomized Controlled Trials (PubMed®)
Urinary Tract Infections and Complementary Health Practices - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Vitamin D - Randomized Controlled Trials (PubMed®)
Vitamin D - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Weight Loss - Randomized Controlled Trials (PubMed®)
Weight Loss - Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Yoga for Health—Randomized Controlled Trials (PubMed®)
Yoga for Health—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Yoga, Meditation, and Chiropractic—Randomized Controlled Trials (PubMed®)
Yoga, Meditation, and Chiropractic—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Yoga—Randomized Controlled Trials (PubMed®)
Yoga—Systematic Reviews/Reviews/Meta-analyses (PubMed®)
Zinc for Common Colds - Randomized Controlled Trials (PubMed®)
Zinc for Common Colds - Systematic Reviews/Reviews/Meta-analyses (PubMed®)