Pill splitting is one of the best ways to save money on pharmaceuticals, including Viagra. Think of it as buying in bulk. A 100mg tablet may cost only a few dollars more than a 50mg tablet. That means you can divide each 100mg tablet and get two 50mg doses for a much cheaper price per dose than if you bought the same number of 50mg tablets. If you take 25mg doses, you'll save even more money.

With any medication in tablet form, you should ask your doctor or pharmacist if it is OK to split the pills. Some drugs should not be split, such as those in capsules or those in an extended release formula. Extended release forms of drugs usually have initials after the drug name to indicate this, such as CR, ER, SR, XL, XR, SA, or LA.

Making the Cut

It can be hard to split pills with absolute precision. Furthermore, although a tablet contains a certain amount of a drug, the active ingredient may not be distributed evenly throughout the tablet. Pill splitting is not a good option if your medication requires a very carefully controlled dosage, such as Coumadin (warfarin). However, for many drugs, including Viagra, the dose doesn't need to be so exact and there won't be any significant effects if you split a table into slightly unequal portions.

Most standard pill cutters easily split a typical round, flat tablet. However, splitting noncircular pills such as those that are oval (like Lipitor), diamond-shaped (like Viagra), or asymmetrical (like Proscar, which is apple-shaped), can be a challenge. For this reason, specialty pill cutters have been developed for individual drugs or tablet shapes. But are they worth the extra expense?

Here's a comparison of a few different types of pills cutters, and a demonstration of other pill cutting methods that do not require a special device. To test how evenly the cutters split the tablets, we weighed each pill before cutting it, and then weighed each individual piece afterwards using a digital scale that is accurate to 0.01 grams (or 10mg). We also weighed the fragments together to determine if there was any measurable loss of material in the splitting process due to crumbling.

Each Viagra tablet we used weighed 0.63g before cutting, or 630mg (100mg of which is the active ingredient sildenafil citrate). Precisely splitting this would give each half a weight of .315g. However, since our scale doesn't register milligrams, only centigrams, we considered a weight of either 0.31g or 0.32g acceptable. Keep in mind that most of the pill is just filler - inert ingredients that act as a carrier, and the actual amount of active ingredient per milligram of material is quite small (about 0.16 mg of active ingredient per mg of tablet), so you would have to alter the weight of a piece of tablet by 6.3mg to make a 1mg difference in the dosage of the actual drug. This is also assuming that the active ingredient is distributed evenly throughout the tablet, which it may not be.

Admittedly, we did not do extensive trials with these cutters. Due to the expense of the materials involved, we limited ourselves to one or two attempts per cutter. However, we think these results are a reasonable demonstration for practical purposes.

Pill Cutter #1: The Premium Model

The web site for this solid titanium splitter states that it is precision machined, and claims it will cut Viagra pills more precisely than any other cutter. Its cutting blades are guaranteed never to dull, and they won't - because they aren't sharp. The "blade" is actually pretty thick; you can run a finger along it without breaking your skin. This device doesn't so much cut the pill as break it by driving wedges into it from the top and bottom, the way you would bite a pill in half with your front teeth.

The cutter has slots for halving both 100mg and 50mg tablets. A 100mg tablet fits well, but there is enough side-to-side play that you have to carefully center the pill to get an even cut. Quartering tablets is more difficult: you have to brace the pill against the top half of the notch and hold it steady from either side with your thumb and forefinger.

The instructions say to push down with your thumb. You have to press very hard, much harder than with other pill splitters, so this probably would not be a good choice for people who have arthritis or a similar condition.

Once the pill split, the break was very clean and straight with hardly any crumbling. The halves looked even and weighed within 0.02g (20mg) of each other (.31 and .30). The combined weight on the scale was .62g, suggesting that the actual difference was <20mg and that the loss of material was 10mg or less. The dosages in each half would be within approximately 1-2mg of each other.

Splitting a half tablet was not as easy, and the results were not as precise because the pill had to be manually held during cutting. The quartered sections split at 0.17g and 0.13g. This represents a dosage difference of approximately 6mg of active ingredient, which could have a noticeable effect on results. In a second attempt, the quarter sections differed by 30mg, or about 5mg of medication.

Pill Cutter #2: The Mid-priced Model

This pill cutter has a custom template that holds the pill in place while it is split. Templates are also available for other drugs, such as Lipitor, Paxil, and Zoloft. Similar cutters use a small tray to hold the pill in place. The splitting mechanism here is a steel razor blade inside the upper part of the device, which is pushed straight down into the pill.

This pill splitter made a fairly clean, even cut with minimal crumbling. Although the pill split completely, the blade did not actually go through to the other side, so part of the outer coating was left intact and connected the two halves. However, they were easily separated and this had no effect on the actual pill itself, although part of the coating peeled off.

The halves weighed .30g and .32g respectively. This difference of .02g (20mg) represents a dosage difference of 3mg of active ingredient per half tablet - probably not a significant amount in this case. This cutter was designed to halve pills only, so we didn't attempt to quarter a tablet with it.

Pill Cutter #3: The Budget Model

This pill cutter is made of plastic, with a single-edge steel razor blade for cutting. This type is inexpensive and available at any drugstore. The pill is held in place in a soft rubber tray, which grips the sides of the tablet and keeps it from slipping. The trick to using this type of cutter is getting the pill lined up precisely so it is cut evenly. This can be difficult with an odd-shaped pill like Viagra, which can easily tilt askew to one side or the other. However, we were able to get a fairly even split, with the halves weighing .30g and .32g, the same as the previous cutter. There was a little bit of crumbling but not much loss of material.

You would think that this type of cutter would work well for quartering a tablet, since the  triangular half-pill would fit nicely in the V-shaped tray. However, the results were not so good: the quarter sections weighed .12g and .18g  - a 40-60% split. This .06g (60mg) difference represents a dosage discrepancy of approximately 9.5mg. The unevenness of the sections was probably also due to the fact that the initial cut halving the pill was made at an angle, so it was impossible to accurately divide the half-tablet by cutting down the middle. Additionally, there was more crumbling, with a small fragment falling off one quarter section.

With a Kitchen Knife

Cutting pills with a kitchen knife is difficult, especially an odd-shaped pill with a hard, slick coating like Viagra. This is not a method we would recommend, unless you had no other options. We suggest the following to increase safety: Use a cutting board as a cutting surface if possible, not a countertop. Fold a paper towel in quarters and lay it on the cutting board to keep the pill from sliding or skidding out from under the knife. Use a serrated knife to carefully cut through the pill coating and score a line where you are going to cut. Place the scored pill on the folded paper towel near one edge and place the knife blade (near the handle, where the blade is straight) in the scored line. Hold the knife perpendicular to the counter as much as possible. Fold the rest of the paper towel over the top of the knife and pill to keep the halves from flying across the room. Put your palm on top of the knife and press straight down.

The results we achieved with this method were marginally acceptable, probably due to the difficulty in scoring the tablet evenly to begin with, stabilizing the pill, and maintaining a precise downward force with the blade. We got a 0.34g and 0.28g split with this method. When we cut a 0.32 half-tablet section, our results were 0.14g and 0.18g. In each case the 40mg difference represents a dosage difference of approximately 6mg, which is significant.

With a Razor Blade

Most pill splitters incorporate single-edge razors as their cutting blades. However, using a single-edge razor by itself to split pills is dangerous. Never hold the pill between your fingers when cutting it - it's too easy for the blade to slip against the hard coating or slide off course as it cuts through the pill.  We used method similar to that we used with the kitchen knife: We scored the coating of the pill and used a cutting board cushioned with a folded paper towel. Gripping the top edge of the razor through a towel, we aligned the blade in the score mark perpendicular to the cutting surface and pressed straight down on the top edge of the razor.

The blade cut through the pill quickly and easily - maybe too quickly and easily. It cut through the first few millimeters of the tablet, veering off at an angle. The result was a very crooked cut and two pieces that weighed 0.28g and 0.34g - the same results we got with the kitchen knife method. Splitting a half tablet was even worse: a .30g half tablet was divided into 0.12g and 0.18g sections. That would represent approximate dosages of 19mg and 28mg of drug respectively.

Of all the cutting methods we tried, using a razor blade was the most imprecise and certainly the riskiest.

Ratings and Recommendations

Here are our ratings of the various cutters/methods that we tried:

Titanium Pill Splitter 

Pill Splitter with Viagra Template 

Drugstore Pill Splitter 

Kitchen Knife 

Razor Blade 

The three pill cutters we tested were all reasonably accurate when splitting a 100mg Viagra tablet in half, and split the tablets without causing much damage or crumbling. Cutters with trays to hold the specific drug may give you more consistent results and are more convenient because they position the tablet for you. If you are going to be splitting tablets a lot, you may want to invest in one. We docked the templated one in our ratings, though, because you can't quarter pills with it.

Given that the differences between the three cutters were small, a basic hinged plastic cutter should be adequate, and has the advantages of being inexpensive and readily available. It's also more versatile because it can be used to split other types of tablets should you need to do so. In other words, a special cutter is not required to split Viagra tablets, nor is it necessarily more accurate, but you may find it easier to use.

Besides precision, a practical consideration is longevity. Both the inexpensive and mid-range cutters use steel razor blades, which will dull with use, meaning the entire cutter will need to be replaced. The premium solid metal cutter would probably last a lifetime. So you should think about how much and how often you expect to be using your pill cutter before you lay out a lot of cash.

As far as quartering a 100mg Viagra tablet, none of the methods we tried were very accurate. However, both the high- and low-end pill cutters were comparably effective, and if you don't mind a minor amount of uncertainty in your dosage, they may work for you. If you want a more accurate 25mg dose of Viagra, we suggest getting 50mg pills and splitting them in half, although this will be more expensive.