This guide is a general-health document for adults 18 or over. Its aim is strictly educational. It does not constitute medical advice. Please consult a medical or health professional before you begin any exercise-, nutrition-, or supplementation-related program, or if you have questions about your health.

This guide is based on scientific studies, but individual results do vary. If you engage in any activity or take any product mentioned herein, you do so of your own free will, and you knowingly and voluntarily accept the risks. While we mention major known interactions, it is possible for any supplement to interact with other supplements, with foods and pharmaceuticals, and with particular health conditions.

Examine.com does not assume liability for any actions undertaken after visiting these pages, and does not assume liability if one misuses supplements. Examine.com and its Editors do not ensure that unforeseen side effects will not occur even at the proper dosages, and thereby does not assume liability for any side effects from supplements or practices hosted under the domain of Examine.com.

Examine.com does not make any representations, recommend or endorse any specific tests, products, procedures, opinions, or other information that may be mentioned on the website. Reliance on any information provided by Examine.com, Examine.com employees, guest writers, editors, and invitees of Examine.com, or other visitors to Examine.com is solely at your own risk.

The Examine team has been publishing research on nutrition and supplementation since March 2011. Drawing from all we’ve learned, we’ve designed this Supplement Guide with two aims in mind: helping you decide which supplements are right for you, based on the scientific evidence, and helping you integrate these supplements into synergistic combos.

Primary supplements have enough research backing them that we’re confident in their effects. Those effects are robust and worthwhile in the contexts in which the studies were conducted. These supplements also have few known safety concerns.

Secondary supplements are lacking in at least one of the following: strength of evidence, magnitude of effect, or safety. A secondary supplement may have substantial evidence behind it, but the conclusion is that it's only modestly effective, or it could appear to be highly effective but the evidence isn't quite there yet. It could also have nontrivial safety concerns that make it less appealing. A secondary option is not for everyone, but if you read the entry and find that it makes sense for you, consider adding the supplement to your combo.

Promising supplements have insufficient evidence to be confident in their effects, but what preliminary evidence there is looks positive. They could work, or they could be a waste of money. Keep them in mind, but think twice before adding them to your combo.

Unproven supplements have insufficient evidence to begin to speculate on their effectiveness. At this point, they are not good candidates for your combo.

Inadvisable supplements are either potentially dangerous or simply ineffective. Do not add them to your combo. At best, they’ll be a waste of money; at worst, they can cause you harm.

Now that you’ve learned of various supplements worthy of your consideration, you’ll learn to integrate them into synergistic combos. You’ll discover a core combo (composed of the supplements that may be beneficial for most people regardless of health status or demographic) and several specialized combos. Each specialized combo is optimized for a specific population. The simplest way to formulate your own combo is to combine the core combo with the specialized combo that best fits your situation, needs, and primary health goal.

Then comes the FAQ, in which we cover common questions that may arise when selecting and combining supplements. With all this, you should be able to identify and assemble the supplement combo best suited to your objective.

In this guide, we address 2 aspects of sexuality: libido (or sex drive: the general desire for sex) and arousal (a stimulated libido and its external signs, such as erections and lubrication).