Penis size is a touchy subject, and according to one estimate, 30% of men are not satisfied with theirs. This can make you self-conscious and feel the need for some type of penis enlargement method.

For reference, according to a 2014 study of over 15,000 men, the average length of a flaccid penis is 3.61 inches and the average length of an erect penis is 5.17 inches.

There are some products on the market that claim to increase penis size. And while some of them may do what they claim, others are dangerous and should be avoided. Here's what you should actually use to increase your penis size versus what you shouldn't.

While these methods may not make permanent changes to your penis size, they can help temporarily, or at least give the illusion of a bigger penis.

Vacuum pumps can help to increase the amount of blood that fills the penis during an erection, says Jessica Yih MD, a urologist who specializes in men's sexual health at The Ohio State University Wexner Medical Center. This can help temporarily increase the size of your erection. 

Yih says pumps are commonly used in conjunction with a penis ring. Penis rings are placed around the base of the penis to help keep the blood in the penis longer during an erection. Pumps will not permanently make your penis bigger.

If you suffer from erectile dysfunction, medications can help. They will not increase the size of your penis, but they may help blood flow to your penis which can result in a bigger and harder erection if you struggle to get one in the first place. This is because these medications contain a chemical called phosphodiesterase type 5 inhibitor, says Yih, which relaxes blood vessels and increases blood flow. Three of these medications include:

These medications must be prescribed by a doctor.

There are a couple of other changes you can make that may cause your penis to appear bigger. One simple fix is to trim pubic hair, says Judson Brandeis, MD, a urologist in private practice. Additionally, if you are overweight, losing weight can also make your penis look bigger. "If you have significant lower abdominal fat, also called a suprapubic fat pad, this can cover up a portion of your penis, making it appear shorter. Losing weight can help to 'uncover' the penis and gain that length back," says Yih.

Some enlargement methods are a waste of time, simply being ineffective. Other methods come with risks of infection or undesirable outcomes. 

While you may see penis enlargement lotions and creams on the market, Brandeis says these have not been proven to be effective in any scientific studies. Yih adds that these products are not FDA-approved. Because of both of these reasons, you should stay away from lotions that advertise penis enlargement. 

Brandeis says there is a stretching technique called jelqing which involves manually pulling on the penis, however, he says there is no scientific evidence that proves it to be effective. "By pulling the penis, you are loosening the suspensory ligaments and allowing the penis to hang lower when flaccid, but it is highly unlikely that the actual penis is getting longer," says Brandeis.

Important: A different situation where stretching exercises may be done is if you have Peyronie's disease, which is abnormal curvature or deformation of the penis, says Yih. In this situation, Yih says stretching exercises may be recommended by your doctor to help correct curvature and regain some amount of length back that was lost due to the curvature.

Fillers or emulsified fat may be injected into the penis to increase the girth of the penis, but not the length, Brandeis says. However, this only lasts about two years, and it can make the penis look uneven because the head of the penis is not affected. Additionally, there is a risk of infection. Overall, it's not ideal.

Furthermore, if fillers are silicone, Yih says this can cause severe inflammation and form scar tissue, which may require corrective surgery. 

Another option is the Penuma implant. Brandeis says this is a taco-shaped piece of silicone that is placed inside the penis. According to the Penuma site, the implant can increase flaccid penis girth and length by one to two inches, but results can vary, and there is a risk of infection. 

This procedure is not for everyone. "Many patients say it feels unnatural. If a man gets it removed, that is catastrophic. There is bad scar tissue and the penis size is shorter, and the erection does not elevate to normal position," says Brandeis. He strongly advises against this surgery. 

Even if you think your penis is on the smaller side, it's likely that it actually falls within a normal range. If you're very concerned about your size, see your primary care physician or a urologist to talk about your options.