There aren't any studies out yet proving that quinoa boosts testosterone or increases erectile strength, but I think it's just a matter of time. This food is a bedroom powerhouse and you can thank the Incan Love gods for it: quinoa comes from the Andes just like Maca and should be a staple of every male concerned with his hormones and erections.
Quinoa is actually not really a true grain and is closer to spinach and tumbleweeds in origin. All we know is that quinoa has many properties that will likely help increase your muscle mass, hormones and bedroom prowess.
Think I'm exagerrating? Here are some great reasons to consider quinoa one of your best bedroom buddies:
1. Ecdysteroids. Some bodybuilders take ecdysteroids for muscle building. Well, the amount of ecdysteroids in quinoa is comparable. 
2. Protein Quality. Plant protein is notorious for a lower "usability". Almost always it is lower in one of the key amino acids such as lysine (in the case of rice) making it not as bioavailable as animals proteins. Quinoa is a rare exception: it's protein is ready to go.
3. Zinc. Move over oysters. One cup of quinoa has about a third of your daily zinc and abundant copper as well. A zinc deficiency can lower testosterone and zinc is also an aromatase inhibitor. Nice! Or you can always do what everyone else does and take Zinc Supplements that lead to arterial inflammtion and/or excitotoxin damage.
4. Magnesium. One cup of quinoa also has almost a full day's RDA of magnesium. Magnesium helps you sleep like a baby and more sleep means more testosterone. Magnesium is also critical for muscle building and many bodybuilders take magnesium supplements for just that reason.
5. SOD. Quinoa is packed with manganese and, as mentioned above, copper, both cofactors in building your body's superantioxidant SOD. SOD protects mitochondria like nothing else and mitochondrial damage is a key cause of andropause.
6. Arginine and Glutamic Acid. One cup of quinoa has 22 grams of protein, which is high for a plant, and - oo la la - about 1.7 grams of L-Arginine and about 3 grams of Glutamic Acid (not to be confused with the excitotoxin). Both of these bad boys can optimize or boost nitric oxide and lower blood pressure. That means more blood flow and better erections.