5 Weird but Beneficial Side Effects of Common Drugs

Fact checked by Heather MercerMedically reviewed by Mary Choy, PharmD

The term "side effect" typically gets a bad rap. Many people think that the side effects of medication are typically undesirable. However, a side effect is simply a secondary consequence of a therapy that is provided to correct a medical condition and can thus be either beneficial or detrimental. On the other hand, "adverse effects," "adverse events," and "adverse reactions" are negative consequences of therapy.

It probably should come as no surprise that many medications have effects that are different from their intended use. After all, once consumed, these drugs circulate throughout the body and are exposed to various organ systems, including the circulatory, respiratory, and nervous systems.

Here are five strange and beneficial side effects of commonly prescribed medications.

Proscar and Hair Growth

Proscar (finasteride) is a medication used to treat benign prostatic hyperplasia (BPH). BPH is a pathological process in which the prostate gland (found in men) compresses the urethra, slowing and/or blocking the flow of urine. BPH is an uncomfortable condition, which results in urinary symptoms, such as urinary frequency, hesitancy, urgency, and weakened stream.

Proscar inhibits 5 alpha-reductase, an intracellular enzyme that converts testosterone to dihydrotestosterone. In doing so, Proscar reduces the size of the prostate during the course of months and alleviates symptoms of urinary obstruction.

The active ingredient in Proscar is finasteride, which is also the active ingredient in Propecia, a drug taken to promote growth in those with male-pattern baldness. In other words, a bald man taking Proscar to treat BPH could also experience hair growth.

Notably, the concentration of finasteride in Proscar is substantially higher than its concentration in Propecia. In other terms, people taking finasteride for BPH take around 5 mg per day for a period of several months; whereas, those taking finasteride for hair loss take about 1 mg per day for a period of several months.

Please check with your physician before taking Proscar, Propecia or any other prescription medication. Your physician will know what dosage and treatments, if any, are right for you.

Baclofen and Heartburn Relief

Baclofen is a skeletal muscle relaxant that inhibits reflexes and muscle spasms by acting on spinal cord nerves. It is used to treat muscle spasticity. Spasticity involves continuous and unwanted contractions of one or more groups of muscle. Spasticity is caused by injury or insult (for example, cerebral palsy, multiple sclerosis or stroke) to the brain or spinal cord.

The severity of spasticity runs the gamut from mild and merely annoying to major and incapacitating. Major spasticity can lead to contractures, immobility, and bedsores (AKA pressure sores or pressure ulcers).

It’s important to treat spasticity because this condition can cause pain, affect mood, interrupt sleep, and impair the mobility as well as confound a person’s ability to partake in activities of daily living, such as hygiene maintenance, using the bathroom, dressing, and eating. Failing to treat spasticity properly can lead to permanent deformity, or maladaptive remodeling, including contracture of tendons and small muscles as well as shortening of muscles.

In addition to treating the various symptoms of muscle spasticity, such as soreness, cramping, and spasms, baclofen may also improve the symptoms of gastroesophageal reflux disease (GERD). GERD is caused by abnormal relaxation of the lower esophageal sphincter (LES), which is located between the esophagus and stomach and allows for the passage of food along the gastrointestinal tract. When the lower esophageal sphincter relaxes abnormally, acidic stomach contents flow back into the esophagus resulting in the symptoms of GERD, such as heartburn, cough, sore throat, chest pain, and difficulty swallowing.

In certain people with GERD, baclofen can improve the symptoms of this condition because it inhibits transient LES relaxations (TLESRs), especially after eating (postprandial). A meta-analysis of clinical trials published in 2014 indicate that this drug significantly decreases the number of TLESRs and incidence of reflux. More recently, a 2023 systematic review of clinical trials also concluded that baclofen is an effective short-term treatment for GERD, ideally as an addition to their current treatment with proton pump inhibitors (PPIs) rather than first-line or stand-alone treatment.

In the past, three pharmaceutical companies have tried to develop new GABA-B agonists for the treatment of GERD, similar to baclofen but with a longer half-life and fewer side-effects: AstraZeneca, Xenoport, and Addex Pharmaceuticals. AstraZeneca’s lesogaberan made it the furthest in clinical testing; however, researchers concluded that this drug was only marginally superior to placebo in reducing GERD symptoms in patients who are only partially responsive (refractory) to PPI treatment.

On further examination, some researchers have suggested that the reason lesogaberan didn’t prove clinically useful in AstraZeneca’s clinical trials is that the patient population of the study was too diverse and should have only included those who predominantly suffered from persistent reflux, or regurgitation, experienced TLESRs as a cause of this reflux, and were not adequately responsive to treatment with PPIs.

In other words, baclofen likely helps people with severe reflux who experience TLESRs after eating and are only partially responsive to current PPI treatment.

At this time, treatment of GERD with baclofen is off-label and typically reserved for people who are refractory to conventional treatment with PPIs.

Viagra and Improved Heart Contractility

We all know that Viagra (sildenafil) helps men have sex. Specifically, it increases blood flow to the penis by relaxing smooth muscle. In addition to facilitating erections, Viagra may also have a very beneficial side effect of improving heart health.

Results from a 2014 meta-analysis published in BMC Medicine suggest that phosphodiesterase type 5 (PDE5) inhibitors, like Viagra, may improve cardiac contractility (inotropism), decrease cardiac mass in patients with left ventricular hypertrophy, and improve cardiac index and ejection fraction. These researchers propose that Viagra and other PDE5 inhibitors may be useful in treating cardiac hypertrophy and early-stage heart failure.

Of note, we still have much to elucidate with respect to the effects of PDE5 inhibitors on heart health. Nevertheless, it’s interesting to note that the benefits of Viagra may extend past the bedroom.

Oral Contraceptive Pills and Improved Acne

Many young women notice that their acne gets better after they take oral contraceptive pills (OCPs) to prevent pregnancy. This improvement is no coincidence and is caused by the hormones present in birth control pills — estrogen and progesterone.

In 2012, researchers belonging to the Cochrane Collaboration did a search for studies that examined the use of OCPs for acne treatment. Their review ended up including 31 studies and 12,579 patients. The review was robust and included clinical trials that compared either two types of birth control pills, a pill and a placebo, or a pill and another acne treatment.

The researchers found that OCPs are effective at reducing the inflammatory and non-inflammatory lesions secondary to facial acne. Furthermore, the researchers discovered that, depending on the specific types and amount of hormones contained in the pill, certain OCPs may be better than others at treating acne. For instance, pills that contained cyproterone acetate (an antiandrogen which is currently not available in the United States) worked better than those with levonorgestrel. On the other hand, progestin-only contraceptive pills are not effective for acne, and may, in fact, exacerbate it.

In the United States, there are currently four OCPs, with a combination of estrogen and progesterone, approved for acne treatment (Ortho Tri-Cyclen 21, Yaz, and others). Please keep in mind, however, that we still don’t know for sure which specific types and combinations of hormones contained in OCPs are best at helping with acne, and any claim that one OCP treats acne better than others is, as of yet, unfounded.

In other words, if one OCP manufacturer happens to advertise that its OCP works better than a rival manufacturer’s OCP, then, as of now, this claim is not based on convincing scientific evidence. Alternatively, if somebody tells you that the current OCP that she takes helps more with acne than a previous OCP that she has taken, this would simply be her personal experience, but there is no current scientific basis for this statement, either. Looking forward, it would be intriguing to examine which types of OCPs help with symptoms of acne most.

Levodopa and Creativity

In the annals of medical literature, there is a long history linking neuropsychiatric conditions and creativity. Physicians have long observed the emergence of some new creative talent after frontotemporal dementia, stroke, or temporal lobe damage.

Physicians, however, have only begun to examine the association between people taking levodopa and other dopamine agonists for Parkinson’s disease and the emergence of newfound creativity. This interest is fueled by accounts of people with Parkinson’s disease who had never before written books and poems that went on to garner literary acclaim. Furthermore, people with Parkinson’s disease who had been taking dopaminergic medications (such as Levodopa) and/or dopamine agonists (such as ropinirole) have been observed to create really voluminous art painted in vivid colors.

Consider the following passage from a 2013 paper published in Behavioral Neuroscience, which expatiates on the role of medications that target dopamine as creativity enhancers:

“It is indeed remarkable that all reported PD [Parkinson’s disease] patients with emergent creativity were treated with dopaminergic agents including levodopa and a dopamine agonist. Although some authors suggested the role of ergot agonists [first generation dopamine agonists], similar phenomena occurred also with nonergots [newer dopamine agonists]. It thus seems the required constellation for emergent new talents or the enhancement of an existing minor one; [sic] in the presence of PD and exposure to levodopa and a dopamine agonist.”

On a final note, the observed link between levodopa administration and creativity is still, at this point, fairly speculative. Other factors may be at play, too, including mechanisms of Parkinson’s disease itself, such as disinhibition or novelty seeking.

Nevertheless, it’s somewhat placatory to think that treatment for Parkinson’s disease, a progressive disorder of the nervous system that gradually depletes a person of movement, may inspire a patient to create beautiful art. Moreover, such artistic creativity can improve the quality of a person’s life and provide needed occupational therapy for those with Parkinson’s disease.