Viagra ( Sildenafil )

Why Isn’t Cialis Recommended To Be Split?

In our latest question and answer, the pharmacist discusses why Cialis tablets are not recommended to be split.

Why is it recommended to not split tablets of tadalafil? I have been splitting the 20 mg tablets and taking them daily for over a year, for ED. What are the problems that could arise if you take split tablets over an extended period of time?

Key points

  • Brand Cialis tablets are not recommended to be split for a variety of reasons (e.g. they have a film-coating and an irregular shape).
  • Generic tadalafil tablets are also not recommended to be split due to the tablets being film-coated.
  • Nevertheless, splitting Cialis and generic tadalafil tablets is a common practice, and it generally shouldn’t result in any significant negative consequences.
  • Neither brand Cialis nor generic tadalafil tablets are scored.

Hello and thank you for your question!

Whether or not a particular drug tablet or pill can be split is one of our most common questions.

In general, if the drug is ‘immediate-release’ (i.e. does not have some sort of extended or delayed-release mechanism), it can be split, but there are exceptions.

Cialis (tadalafil) is one of those exceptions.

Can You Split Cialis?

As you stated in your question, you are correct that the manufacturer of Cialis ( tadalafil ) recommends not to cut or split the tablets. Per the prescribing information

The labeling for both the brand name Cialis and generic tadalafil tablets (all manufacturers) explicitly states that the tablets should not be split, as shown in the image of two labels below:

There are a few reasons why it is recommended for Cialis tablets to stay intact, but overall, the potential consequence of splitting tablets is likely, not significant.

In fact, it is not uncommon for prescribers to recommend splitting Cialis tablets as a potential cost-saving measure for patients.

Why Shouldn’t Cialis Be Split?

There are two main reasons why Cialis (and associated generic) tablets are not recommended to be cut or split:

  • Brand name Cialis tablets have a non-symmetrical shape.
  • Generic tadalafil tablets, many of which are symmetrical, are film-coated (brand Cialis is film-coated too). Splitting these tablets will destroy the film-coating.

Aside from the two reasons above, other reasons exist for the recommendation not to split the tablets. They include:

  • Split Cialis tablets have not been tested for safety or efficacy.
  • Neither the brand nor the generic tablets are scored.

Shape Of The Pill

Brand name Cialis tablets, like Viagra, have an odd, non-symmetrical shape. Below is an image of the 20 mg Cialis tablet:

The non-symmetrical shape of Cialis tablets would make it difficult to evenly split into two pieces. This may lead to inconsistent dosing.

Generic Cialis products (tadalafil) are recommended not to be split too, even though most of them are symmetrical in shape. The recommendation not to split these is likely mostly due to the film-coating.

It is important to point out that neither the brand nor the generic tablets are scored. Even with the use of a pill splitter, non-scored tablets can be difficult to split evenly.

Lack Of Data

During clinical trials for Cialis, the manufacturer (Eli Lilly) only looked at the use of whole tablets. There is no safety or efficacy data on the use of split tablets. Therefore, the generic products have no data on split tablets either.


Brand and generic tadalafil tablets are film-coated. Splitting the tablets destroys the film coating.

There are a variety of reasons why a drug tablet may be film-coated, including:

  • They are often easier to swallow and less likely to cause throat irritation than non-coated tablets.
  • Some film coatings are designed to protect the tablet from dissolving in the stomach. This can not only reduce the potential of certain side effects (e.g. nausea), it can also help to make the drug more effective by preventing early degradation by stomach acid.

According to the prescribing information for both Cialis and generic tadalafil products, the film coating is not a delayed-release mechanism and is therefore likely intended only to ease swallowing and to protect the tablets from excess moisture.

What Happens If You Do Split Them?

Having said all of the above, splitting/cutting erectile dysfunction (ED) drugs like Cialis is a fairly common practice. Your doctor may even recommend you do it if you need to adjust your dose or as a cost-saving measure.

There have been no reported safety issues cutting Cialis (or generic tadalafil) tablets, and they are not listed on the ISMP list of medications that shouldn’t be crushed.

If you have the brand-name tablets, and your doctor has recommended splitting them to adjust your dose or as a cost-saving measure, take care in doing so since it can be difficult to cut the oddly shaped tablets (and they aren’t scored).

If you have a generic tadalafil tablet, most are symmetrical and should be easier to split evenly when compared to the brand-name ones.

However, be aware, if you do split the tablets, they may be slightly more difficult to swallow since the film-coating will no longer be intact. They may also have an unpleasant taste.