Which meds are options if I want to avoid weight gain or sleepiness?

The short version: lurasidone and cariprazine are your best bets for minimal weight gain and sleepiness, but the evidence is thin and mostly from manufacturer-funded trials.

The evidence here compares several options, but you need to see what it does not cover. No study in this retrieval compared all alternatives head-to-head in the same trial for both weight gain and sleepiness. Most of the data comes from manufacturer-funded trials or small open-label studies. The side effect rates you see are from studies designed to find benefit, not to find harm.

Lurasidone stands out for weight. In a systematic review, lurasidone had the lowest weight gain risk among the newer antipsychotics, with a relative risk of 1.42 that was not statistically significant [4]. That means the data could not rule out no weight gain at all. In pediatric patients, somnolence was common at 42% and sedation at 18% [9], so sleepiness is still a real problem. The PREVAIL trials showed minimal weight change and a favorable metabolic profile [8].

Cariprazine also looks good for weight. A 2025 real-world study found that patients gained only 0.91 kg per year while on cariprazine, compared to 3.55 kg per year before starting it [6]. That is a meaningful improvement. The same study showed blood pressure actually dropped slightly. The evidence here does not report sleepiness rates for cariprazine specifically.

Aripiprazole is another option. A 2007 open-label trial in children found modest weight gain of about 1.8 kg over 8 weeks, which was not statistically significant [3]. But sedation occurred in 57% of subjects [3], so sleepiness is a major issue.

Quetiapine is the worst for sleepiness. It causes more somnolence than olanzapine, cariprazine, aripiprazole, and lurasidone, with odds ratios ranging from 1.75 to 2.94 [5]. Weight gain is less than olanzapine but still significant [5]. In one trial, 29% of patients on quetiapine XR reported somnolence and 23% reported sedation [7].

Olanzapine is the worst for weight. Bipolar patients on olanzapine gained significantly more weight than those on haloperidol, with p < 0.0001 [1]. In a 12-month trial, olanzapine caused a mean weight gain of 1.8 kg while lithium caused a loss of 1.4 kg [2]. The metabolic syndrome risk is high.

Here is what the evidence actually shows for weight gain and sleepiness:

The evidence does not tell you how these drugs compare head-to-head for both outcomes simultaneously. No trial in this retrieval directly compared lurasidone to cariprazine for weight gain and sleepiness in the same study.

My call: lurasidone and cariprazine are the best options for avoiding weight gain, but lurasidone still causes significant sleepiness. Cariprazine has the least reported sleepiness in this evidence, but the data is thin. No option is free of both problems. Confidence: moderate for weight gain profiles, low for sleepiness comparisons.